SC802

SC802_08 SEMTECH | Alldatasheet

Document overview

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Technical content

Features

Integrated charger with pass FET, reverse-blocking diode, sense resistor, timer, and thermal protection Battery Voltage — 4.1V, 4.2V, and adjustable Programmable pre-charge, fast-charge, & termina- tion current Battery voltage controlled to 1% accuracy Soft-start for glitch-free adaptor plug-in Continuous charge current — Up to 1.5A Charge current monitor output for microcontroller or ADC interface Input voltage range — 4.3V to 14V Battery Drain when not charging — 0.1μA Operates without a battery in regulated LDO mode Small 4 x 4(mm) 16 lead MLPQ package NTC thermistor sense input Adjustable up to 6 Hour programmable charge timer Over-current protection in all charging states Over-voltage protection Remote Kelvin sensing at the battery terminals ADC input current control capable Status output for charging and end of charge cycle Charges Li-Ion, Li-Polymer, NiCd, and NiMH Batteries

Applications

Cellular phones and PDA’s Handheld meters Charging stations Handheld computers Digital cameras Programmable current source

Description

The SC802 and SC802A are fully integrated, single cell, constant-current/constant-voltage Lithium-Ion/Lithium Polymer battery chargers. With an integrated timer and complete charge control algorithm, the devices are opti- mized for stand-alone charger applications. They provide for programmable pre-charge, fast-charge, and termina- tion current settings. The devices can be programmed to terminate the charge cycle based on the output current or the time-out of the programmable timer. The fast-charge current is typically set with an external resistor but can be modified with the analog fast-charge input to allow a Power Management Controller to control the fast-charge current setting via DAC. The 14V input voltage range of the SC802 and SC802A eliminates additional protection circuitry required by other 5V chargers in the event of faulty adapters. Reference ground and battery sense inputs are provided to allow Kelvin connections, to eliminate errors due to I×R voltage drops during charging. The output voltage to the battery is controlled to within 1% of the programmed voltage for either 4.1V or 4.2V. The SC802 and SC802A can also function as a general purpose current sources, such as for charging nickel-cadmium (NiCd) and nickel-metal-hydride (NiMH) batteries. The SC802A version of the device is optimized for high termination current applications. CHARGER VIN RNTC Battery Thermistor AFC ISET RNPU RRTIME CVCC 1μF RIPRGM CVOUT 2.2μFRITERM BAT. CHARGE CHARGER PRESENT SC802/SC802A VCC1 BSEN IPRGM EN_NTC ITERM VOUT2 RTIME CHRGB VPRGM CPB RFGND BIPB VCC2 GND VOUT1 AFC Typical Application Circuit October 30, 2008

© 2008 Semtech Corporation SC802/SC802A Pin Confi guration Marking Information

Ordering Information

SC802IMLTRT(1)(2) MLP16 SC802AIMLTRT(1)(2) MLP16 SC802EVB(3) Evaluation Board SC802AEVB(3) Evaluation Board Notes: (1) Available in tape and reel only. A reel contains 3,000 devices. (2) Available in lead-free package only. Device is WEEE and RoHS compliant. (3) Specify the part number when ordering. BSEN ITERM VPRGM IPRGM TOP VIEW 16 15 14 13 5678 T AFC RTIME CPB CHRGB REFGND GND EN_NTC BIPB VOUT2 VOUT1 VCC2 VCC1 802 yyww MLP-16, 4x4, 16 LEAD θJA = 50°C/W yyww = datecode 802A yyww yyww = datecode

© 2008 Semtech Corporation SC802/SC802A Exceeding the above specifi cations may result in permanent damage to the device or device malfunction. Operation outside of the parameters specifi ed in the Electrical Characteristics section is not recommended. NOTES: (1) VCC1 and VCC2, and VOUT1 and VOUT2, must be connected, and will be referred to collectively as VCC and VOUT, respectively. All references to VVCC, VVOUT, IVCC, and IVOUT refer to the common node voltage and total current of VCC1 and VCC2, and VOUT1 and VOUT2, respectively. (2) Tested according to JEDEC standard JESD22-A114-B. (3) Operating voltage is the input voltage at which the charger is guar anteed to begin operation. Maximum operating voltage is the maximum Vsupply as defi ned in EIA/JEDEC Standard Number 78, paragraph 2.11. (4) Calculated from package in still air, mounted to 3 x 4.5(in), 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards. Absolute Maximum Ratings VOUT Short to GND Recommended Operating Conditions Thermal Information Thermal Resistance, Junction to Ambient (4) (°C/W) . . . . 50 Parameter Symbol Conditions Min Typ Max Units VCC UVLO Rising Threshold VT UVLOR 3.7 4.0 4.3 V VCC UVLO Hysteresis VT UVLOH 40 mV VCC OVP Rising Threshold VT OVPR 6.5 6.8 7.5 V VCC OVP Falling Threshold VT OVPF 6.1 6.5 7.1 V VCC OVP Hysteresis VT OVPH VTOVPR - VTOVPF 200 300 500 mV Operating Current ICCDIS VEN_NTC = 0V, CHRGB, CPB off 2.6 mAICCCHG VEN_NTC = 0.5 × VVCC, CHRGB, CPB off 1 2.4 3.5 ICCLDO LDO Mode, CHRGB, CPB off 81 62 3 Battery Leakage Current (sum of IVOUT and IBSEN) ILeakBAT VVCC = 0V, VVOUT = VBSEN = 4.5V 0.1 2 μA Regulated Voltage VCV-HI VVPRGM = VVCC 4.16 4.20 4.24 V VCV_LO VVPRGM = 0V 4.06 4.10 4.14 REFGND Output Accuracy VVOUT_RGND VVOUT_RGND = VVOUT - VCVn, VREFGND = 30mV 22 30 38 mV REFGND Current IREFGND VREFGND = 0V 35 μA

Electrical Characteristics

© 2008 Semtech Corporation SC802/SC802A Parameter Symbol Conditions Min Typ Max Units Adjust Mode Feedback Voltage V ADJMF VPRGM = External Divider, 4.2V ≤ VCC ≤ 6.5V 3.0 V Adjust Mode VPRGM Shunt Resis- tance RVPGMSH Adjust Mode, VVPRGM = 0.1V 0.5 1 5 kΩ Adjust Mode Threshold Voltage VTADJM VVOUT - VBSEN 50 250 420 mV SC802 Pre-Charge Current IPREQ RITERM = 3.01kΩ 74 82 90 mA SC802 Termination Current ITERMQ RITERM = 3.01kΩ 35.5 42 49.5 mA SC802 Fast-Charge Current IFastQ RIPRGM = 3.01kΩ, VVOUT = 3.8V 450 500 550 mA SC802 AFC Fast-Charge Current IFQ_ADJ RIPRGM = 3.01kΩ, VAFC = 0.75V 200 240 280 mA SC802A Pre-Charge Current IPREQA RITERM = 976Ω 135 145 160 mA SC802A Termination Current ITERMQA RITERM = 976Ω 135 145 160 mA SC802A Fast-Charge Current IFastQA RIPRGM = 1.78kΩ, RITERM = 976Ω, VVOUT = 3.8V 740 800 860 mA SC802A AFC Fast-Charge Current IFQ_ADJA RIPRGM = 1.78kΩ, RITERM = 976Ω, VAFC = 0.75V, VVOUT = 3.8V 310 367 430 mA IPROG Regulated Voltage VIPRGM 1.4 4.5 1.6 V VVOUT Pre-charge Threshold (2) VTPreQ measured at VOUT pins 2.7 2.8 2.9 V VVOUT Re-charge Threshold (3) VTReQ VCV (at BSEN) - VBSEN-FDBK 70 100 140 mV Over Temperature Shutdown TOT-R Hysteresis = 10°C 150 °C EN_NTC Thresholds VTNTC_DIS Disable (Falling) 0.5 <1 1.1 V RTNTC_HF NTC Hot (Falling), tested at VVCC = 5V 28 30 32 % RTNTC_CR NTC Cold (Rising), tested at VVCC = 5V 72 75 78 % RTNTC_EN Charger Enable, tested at VVCC = 5V 84 90 92 % VTNTC_HYS Hot/Cold threshold hysteresis, tested at VVCC = 5V 50 mV Timer Disable Threshold VT TIMER VRTIME < VTTIMER Disables Timer 0.7 1 1.1 V Internal Timer Select VT INTTS VCC-VRTIME < VTINTTS selects internal timer 1.5 V External RTIME Voltage V RTIME RTIME tied through 36.5kΩ to GND 1.4 1.5 1.6 V Pre-Charge Fault Time-out T PreQF RTIME tied through 36.5kΩ to GND 50 min RTIME tied to VCC -35% 45 +35 Charge Complete Time-out T QCOMP RTIME tied through 36.5kΩ to GND 3.3 hr RTIME tied to VCC -35% 3 +35 Electrical Characteristics (continued)

© 2008 Semtech Corporation SC802/SC802A Parameter Symbol Conditions Min Typ Max Units CHRGB Charge LED On V CHRGB Load = 5mA 0.5 1 V CHRGB Charge LED OFF I CHRGB Leakage Current, V = 5V 1 μA CPB LED On V CPB Load = 5mA 0.5 1 V CPB LED Off I CPB Leakage Current, V = 5V 1 μA BIPB, VPRGM Inputs VIH 1.8 V VIL 0.4 Electrical Characteristics (continued) Notes: (1) Electrical Characteristics apply for V VIN = 4.75V to 5.25V, but are tested only at VVIN = 5.00V, unless noted. (2) Pre-charge threshold is applied directly at VOUT for any setting of V CV, whether 4.1V or 4.2V fi xed, or Adjust Mode. (3) Re-charge threshold is relative to V CV as measured at BSEN. For either of the fi xed output voltage settings, V BSEN is compared directly to the programmed CV regulation voltage. In Adjust Mode, V BSEN is compared to the Adjust Mode feedback voltage, V ADJMF. So the re-charge threshold at the battery is VTReQ × VCV / VBSEN-FDBK.

© 2008 Semtech Corporation SC802/SC802A Typical Characteristics Output Current (SC802) versus RIPRGM 0.5 1.5 RIPRGM (k ) Current (A) IFQ 100 150 200 250 RITERM (k ) Current (mA) IPQ ITERM 10 20 40 60 80 Time-out (hrs) TPreQ TQCOMP RRTIME (k ) 100 200 300 400 500 600 700 100080060050045030025020010054 Output Current (mA) Dropout Voltage (mV) 3.2 3.4 3.6 3.8 4.2 4.4 0 25 50 75 100 125 150 175 200 225 t (minutes) VOLTAGE (V) 0.1 0.2 0.3 0.4 0.5 0.6 CURRENT (A) VVOUT IVOUT VCHRGB Output Current (SC802) versus RITERM Drop-out Voltage versus Output Current Time-out versus Output R RTIME Battery Charge Profi le Ω ΩΩ

© 2008 Semtech Corporation SC802/SC802A Pin Descriptions Pin # Pin Name Pin Function

1 BSEN

Battery voltage sense pin — Connect to battery terminal to Kelvin sense battery voltage, to a resistor divider network for adjustable output voltage, or to VOUT otherwise. Do not leave this pin fl oating. 2 VPRGM Selectable voltage program pin — Logic low = 4.1V; Logic high = 4.2V; Resistor = adjustable.

3 IPRGM Charger current program pin in fast-charge mode — Requires a resistor to ground to program

fast-charge current. 4 ITERM Selection for current termination and pre-charge current — Requires a resistor to ground to pro- gram pre-charge and termination current. 5 REFGND Reference ground — Allows Kelvin connection to battery negative terminal.

6 GND Ground

7 EN_NTC Combined device enable/disable and NTC input pin — Logic high enables device; logic low dis-

ables device. Analog voltages between 0.3×V VCC and 0.75×VVCC enable the NTC function. 8 BIPB Battery In Place Bar (BIPB) — selects Charge/LDO mode. BIPB = Low selects charge mode. BIPB = High selects LDO mode which disables Pre-Charge and timer functions 9 AFC Analog fast-charge setting — Connect to DAC for analog control of fast-charge current value. Connect to VCC to disable AFC. Do not leave open. 10 CHRGB Open drain charger status pin — The output is active low when the charger is on and IVOUT > ITERM. The CHRGB output switches to high impedance when IVOUT < ITERM. This pin can sink 10mA. 11 CPB Open Drain Charger present indicator — The output is active low when the VVCC exceeds VTUVLOR. This pin can sink 10mA.

12 RTIME

Programmable timer input pin — Connect to VCC to select the internal time-out of 3hrs. Connect an external resistor to ground to program the timeout period. Connect to ground to disable the timer. 13 VCC1 Supply pin — Connect to adaptor power and to VCC2. (1) 14 VCC2 Supply pin — Connect to adaptor power and to VCC1. (1) 15 VOUT1 Charger output — Connect to battery and to VOUT2. (2) 16 VOUT2 Charger output — Connect to battery and to VOUT1. (2) T Thermal Pad Pad is for heatsinking purposes — The thermal pad is not connected internally. Connect exposed pad to ground plane using multiple vias. Notes: (1) VCC1 and VCC2 must be connected. VCC1 and VCC2 will be referred to collectively as VCC. All references to V VCC and IVCC refer to the common node voltage and total current of VCC1 and VCC2. (2) VOUT1 and VOUT2 must be connected. VOUT1 and VOUT2 will be referred to collectively as VOUT. All references to V VOUT and IVOUT refer to the common node voltage and total current of VOUT1 and VOUT2.

© 2008 Semtech Corporation SC802/SC802A Block Diagram Vout Timer NTC VCC ITERM BIPB Over Voltage VOUT Reference Voltages 4.2V 4.1V Fast Charge Ref Pre-Charge Ref Fast Charge Ref Pre-charge Ref VPROG Mode Detect Vout Programmable Interface Control BSEN AFC EN-NTC RTIM CPB CHRGB REFGND VPRGM GND GND IPRGM ITERM Pre-Charge On Fast Charge On Under Voltage Over Temp Charge/LDO On 13 14 VOUT

© 2008 Semtech Corporation SC802/SC802A General Operation The SC802 and SC802A can be confi gured independently with respect to fast-charge and termination current, output voltage, timing, and operation with and without a battery (LDO mode). A typical charging cycle is described in this section. Details on alternate applications and output programmability are covered in subsequent sec- tions. Wherever the SC802 and SC802A descriptions are the same, the part will be referred to as the SC802/A. The charging cycle begins when the adapter is plugged in. The SC802/A performs glitch fi ltering on the VCC input and initiates a charge cycle when V VCC > VTUVLOR. The CPB and CHRGB signals turn on the charger LED’s. If the battery voltage is less than 2.8V, the SC802/A will charge the output with the pre-charge current. When the battery voltage exceeds 2.8V, the SC802/A enters fast-charge or Constant Current (CC) regulation. When the battery voltage reaches its fi nal value, the charger enters Constant Voltage (CV) regulation. The CV regulation output voltage, CV ), can be programmed to fixed values V CV-HI = 4.2V, VCV-LO = 4.1V, or programmed to any voltage V CV-ADJ using the available Adjust Mode. In CV regulation the battery accepts decreasing current until the output current (I VOUT) reaches the programmed termination current, designated TERM). When IVOUT < ITERM, an event known as charge termination, the CHRGB status indicator turns off, but the SC802/A continues to hold the battery in CV regulation until the timer cycle is completed. At this point the charger enters the monitor state where the output remains off until V VOUT drops by VTReQ, nominally 100mV, and a new charge cycle is initiated. Termination Current When the battery reaches the CV voltage (VCV), the charger transitions from a constant current source to a constant voltage source. The current through the battery begins to decrease while the voltage remains constant until the current decreases below the programmed termination current set by the ITERM pin resistance to ground. Upon termination, the SC802/A will turn off the CHRGB status indicator. If the timer is enabled, the output will remain in CV regulation until the timer cycle is complete. If the timer is disabled, then the output will turn off as soon as the termination current level is reached. The termination current is programmed according to the following equations. 88R 5.1I ITERM TERM u (SC802) 97R 5.1I ITERM TERM u (SC802A) The termination current is programmable up to 67mA for the SC802, and up to 150mA for the SC802A. Pre-Charge Pre-charge regulation is automatically enabled when the battery voltage is below the pre-charge threshold, VTPreQ, nominally 2.8V. Pre-charge is required to precondition the battery for fast-charging, and to limit the power dis- sipation in the charger. The pre-charge current value, I PQ, is determined by the ITERM pin resistance to ground. The pre-charge current is programmable from 10mA to 125mA with the SC802, and up to 150mA with the SC802A. The pre-charge current is given by the following equations. 88R 8.2I ITERM PQ u (SC802) 97R 5.1I ITERM PQ u (SC802A) If the charge timer is enabled, a pre-charge timer is also enabled. If the pre-charge time exceeds 1/4 of the pro- grammed total charge time, the charger will turn off and a pre-charge fault will be indicated by blinking the CHRGB status indicator. This fault is cleared when the charger is disabled (by grounding the EN_NTC pin), or the VCC input voltage is cycled, or the output voltage rises above 2.8V. Fast-Charge Fast-charge or CC regulation is active when the battery voltage is above VT PreQ and less than V CV, the fi nal fl oat charge voltage of the battery. The fast-charge current can be set to a maximum of 1.5A and is selected by the program resistor on the IPRGM pin. The voltage on this pin represents the current through the battery. It enables a microprocessor via an Analog-to-Digital Converter (ADC) to monitor battery current by sensing the voltage Applications Information

© 2008 Semtech Corporation SC802/SC802A Applications Information (continued) on the IPRGM pin. The fast-charge current is given by the following equations. 1000R 5.1I IPRGM FQ u (SC802) TERM IPRGM FQ I3.01000R 5.1I uu (SC802A) Note that for a given program resistor the current through the battery in CV regulation can be determined by replac- ing 1.5 with the actual voltage on the IPRGM pin in the equations. In the case of the SC802A, the I TERM term applies only prior to termination (while CHRGB is low), and should be excluded following termination. The CC current can also be modified by applying an analog voltage to the AFC pin as described in the next section. Analog Fast-Charge Many applications require more than one current setting for fast-charge. This feature is included in the SC802/A by using the AFC function. When the AFC pin is connected to VCC the SC802/A operates as described in the previous section. When the AFC pin is driven by an analog voltage between 0 and 1.5V the SC802/A automatically uses this pin voltage to set the maximum fast-charge current setting according to the following equation. 1000R VI IPRGM AFC AFQ u (SC802) TERM IPRGM AFC AFQ I3.01000R VI uu (SC802A) Monitor State When a charge cycle is completed, the SC802/A output turns off and the device enters monitor state. If the voltage of the battery falls below the re-charge voltage of V CV − VTReQ, nominally 100mV below V CV, the charger will clear the charge timer and re-initiate a charge cycle. The maximum current drain from the battery during monitor state is less than 1μA over temperature. The status of the charger output as a function of BIPB, timer status, and I VOUT in the following table. Output State BIPB Timer I VOUT On High N/A N/A On Low t < T QCOMP N/A Off Low t > T QCOMP N/A Off Low Disabled < I TERM Charge Timer The timer in the SC802/A provides protection in the event of a faulty battery, and maximizes charging capacity. Connect the RTIME pin to VCC to select the internally programmed timer, and to GND to disable the timer. Connecting a resistor between the RTIME pin and GND will program the total charge complete time T QCOMP according to the following equation. R RTIME (kΩ) = TQCOMP (hours) x 12.5 (kΩ/hour) The timer is programmable over the range of two to six hours. The internal timer selection provides a charge time of three hours. The SC802/A automatically turns off the output when the charge timer times out, and then enters the Monitor State. A re-charge cycle resets and restarts the timer. Note that the CHRGB fault indication blink rate is a func- tion of the timer setting, whether externally programmed or set internally. When the timer is disabled, the blink rate is the same as if the timer were internally set. EN_NTC Interface The EN_NTC pin is the interface to a battery pack temper- ature sensing Negative Temperature Coefficient (NTC) thermistor. It can be used to suspend charging if the battery pack temperature is outside of a safe-to-charge range. The EN_NTC interface also serves as a charger disable or NTC–unconditional enable input. The recommended EN_NTC network is a fixed-value pullup resistor (designated R NPU) from the EN_NTC pin to the VCC pins, and the battery pack NTC thermistor (desig- nated R NTC) from the EN_NTC pin to ground. In this con- fi guration, shown in the Typical Application Circuit on

© 2008 Semtech Corporation SC802/SC802A page 1, an increasing battery temperature produces a decreasing NTC pin voltage, designated VEN_NTC. When VEN_NTC is greater than the high (cold) threshold (but below the Charger Enable threshold) or less than the low (hot) threshold (but above the Disable threshold), the charge cycle is suspended, turning off the output. This suspends but does not reset the charge timer, and indi- cates a charging fault by blinking the CHRGB status indi- cator. Hysteresis is provided for both high and low NTC thresholds to avoid chatter at the NTC temperature fault thresholds. When V EN_NTC returns to the Temperature-OK- to-Charge range, the charge timer resumes, CHRGB is asserted (pulled low), the charging output is enabled, and the charge cycle continues. The timer will expire when the output on-time exceeds the timer setting, regardless of how long it has been disabled due to an NTC fault. All EN_NTC input thresholds are proportional to the VCC pin voltage (V VCC). When the recommended external NTC circuit is used, the external EN_NTC pin voltage is also proportional to V VCC, varying with the thermistor resis- tance. This ensures that all EN_NTC thresholds are insensi- tive to V VCC. The ratiometric hot and cold thresholds are given by the parameters RT NTC_HF and RT NTC_CR . V EN_NTC between RTNTC_HF ×VVCC and RTNTC_CR ×VVCC indicates the battery temperature is safe to charge, and enables charg- ing. See the following table. EN_NTC Pin Ratiometric Thresholds % of VVCC Range VEN_NTC Ratiometric Thresholds RTNTC_EN = 90% Charger Enable NTC Cold Fault RTNTC_CR = 75% NTC Temperature- OK-to-Charge RTNTC_HF = 30% NTC Hot Fault RTNTC_DIS = 1V Charger Disable When VEN_NTC < 1V approximately, the SC802/A charger is disabled. This allows the system controller to asynchro- nously disable or reset the device by pulling EN_NTC to ground, using for example an n-channel FET. When dis- abled, the charger is turned off , the charge timer is reset, Applications Information (continued) and CHRGB is turned off (high). The behavior of CPB diff ers between the SC802 and SC802A when the device is disabled. See the Status Indicators section. Charger Enable is selected when the battery (along with the thermistor) is removed, determined by the NTC pin exceeding RT NTC_EN × VVCC, nominally 90% of the VCC pin voltage. Charger Enable behaves identically to NTC safe- to-charge. Charger Enable also provides a convenient means to operate the SC802/A in applications without a battery thermistor, without requiring a passive resistor network to obtain 50% of V VCC. Connect EN_NTC directly to VCC, or via a pullup resistor if it will be necessary to disable the charger by pulling EN_NTC to ground. The response of the SC802/A to an EN_NTC pin voltage above the NTC Cold Fault threshold (but below RT NTC_EN) or below the low NTC Hot Fault threshold (but above VT NTC_DIS) is the same. Therefore the EN_NTC network can be confi gured with the battery pack thermistor between EN_NTC and VCC, and a fi xed resistor between EN_NTC and ground, reversing the designation of the hot and cold thresholds. This confi guration may be used to disable the charger when the battery pack is removed. For detailed design guidance for ratiometric NTC inter- faces, including thermistor selection guidelines, see the Semtech Application Note AN–PM–0801, NTC Thermistor Network Design for Ratiometric Thresholds. Status Indicators There are two status indicator outputs on the SC802/A — CHRGB (Charge) and CPB (Charger Present). These outputs are open drain n-channel MOSFET drivers suit- able for driving LEDs directly. The following table defi nes each output state.

(1) Output remains on when timer is enabled and t < TQCOMP. The CPB output can be used as a VCC–valid detector. (high) when the charger is disabled, regardless of VVCC. conditions are shown in the following table. 4.1V or 4.2V a resistor divider is required. Figure 1. VCV Adjust Mode programming.

© 2008 Semtech Corporation SC802/SC802A the VPRGM pin with the divider tap connected to the BSEN pin to utilize this feature. The Adjust Mode CV regulation voltage is set by the following equation. 0.3R R1V LOADJ HIADJ ADJCV u¸¸ To ensure detection of VCV Adjust Mode, R ADJ–HI should be at least 130kΩ. The capacitor across RADJ–HI in the feedback network provides zero-pole frequency compensation for stability. Place the zero according to the following equa- tion to ensure stability. kHz1002 1CR ADJHIADJ uS u In V CV Adjust Mode, V CV–ADJ must satisfy V VCC > V CV–ADJ + 150mV to ensure regulation. If V VCC approaches V CV–ADJ, VCV–ADJ will drop out such that VCV–ADJ will be approximately VVCC – 150mV. LDO Mode The SC802/A can operate with or without a battery. If the battery is not in place the device can enter LDO Mode. The input pin BIPB is used to switch the SC802/A from charger mode to LDO mode. If this pin is driven logic high the device will be in LDO mode, if it is logic low it will be in the charger mode. The BIPB pin should never be left fl oat- ing. It should be tied through pull-up or pull-down resis- tors when connected to a high impedance control pin or it can be connected directly to the VCC pin or GND. In LDO Mode the SC802/A will function as a low dropout voltage regulator. The EN_NTC pin functions remain active, and the status indicators are active, including the CHRGB indicator. The timer is inactive. The output remains enabled even when I VOUT < ITERM. The output voltage can be set to 4.1V, 4.2V or externally set by a resistor divider, with a current limit equal to I FQ. The pre-charge threshold is ignored. Remote Kelvin Sensing at the Battery Kelvin sensing of both the positive and negative terminals of the battery is available on the SC802/A. The BSEN pin provides the positive sensing voltage feedback to the CV amplifi er and should be connected as close to the battery positive terminal as possible. The REFGND pin should be Kelvin connected to the negative terminal of the battery. This provides maximum fl exibility in PCB layout. This also results in a greater accuracy in sensing the battery voltage at the battery terminals. When laying out the PCB the designer should route the BSEN pin directly to the battery terminal connections. (For Adjust Mode, the high-side resistor should be connected directly to the battery termi- nal connections.) In LDO mode, as in Charging mode, the BSEN pin must sense the output voltage, so BSEN should never be left unconnected. Over-Current and Max Temperature Protection Over-current protection is inherent in all modes of opera- tion. When the device is in charge-mode (BIPB=low) the output is current limited to either the pre-charge current limit value or the fast-charge current limit value depend- ing on V VOUT. When the device is in LDO mode (BIPB = high) the output current is limited to the fast-charge current limit. Maximum die temperature protection is provided on the SC802/A. This feature allows the SC802/A to operate with maximum power dissipation by disabling the output current when the die temperature reaches the over temperature limit. The device will then operate as a pulse charger in extreme power dissipation applications, delivering the maximum allowable output current while regulating the internal die temperature to a safe level. Capacitor Selection Low cost, low ESR ceramic capacitors such as the X5R and X7R dielectric material types are recommended. The VOUT pin capacitance range is typically 1μF to 4.7μF, but C VOUT can be as large as desired to accommodate the required input capacitors of regulators connected directly to the battery terminal. The VCC pin input capacitor C VCC is typically between 0.1μF to 1μF, but larger values will not degrade performance. Capacitance must be evaluated at the expected bias voltage (V CV for CVOUT, the expected VCC supply regulation voltage for C VCC), rather than the zero- volt capacitance rating. Applications Information (continued)

© 2008 Semtech Corporation SC802/SC802A State Diagram Shutdown Mode VOUT off CHRGB High Z CPB Low Soft Start CC Mode Start Pre-Charge Yes IVOUT = IFQ IVOUT = IFQ Monitor Mode VOUT is off Float Charge Mode VVOUT = VCV Soft Start Yes Charger Enabled? BIPB = Low? Start Timer VVOUT > VTPreQ ? t > TPreQF = TQCOMP / 4 ? IVOUT < ITERM ? VVOUT = VCV ? Start CV Regulation CHRGB Low CHRGB High Z VVOUT < VCV - V TReQ ? Pre-Charge Timeout Fault CHRGB blinks at 0.5Hz Cleared by VVOUT > 2.8V or Re-cycle EN or VCC NTC Temperature Fault CHRGB blinks at 0.5Hz Timer is frozen Charge resumes when NTC Temperature is valid VEN_NTC < RTNTC_HF × VVCC or VEN_NTC > RTNTC_CR × VVCC Yes Yes Yes Yes Yes Yes Start LDO Mode IVOUT < ITERM ? CHRGB High Z Float Charge Mode t > TQCOMP ? Timer Enabled? t > TQCOMP ? VVOUT < VCV - V TReQ ? Yes Yes VTUVLO < VVCC < VTOVP Over Voltage or Under Voltage will disable (and reset) the SC802/A, regardless of charger state. Over Temperature will turn off output but preserve charger state. Yes Yes VVOUT = VCV Yes CC = Constant Current CV = Constant Voltage Timer Enabled?

© 2008 Semtech Corporation SC802/SC802A Charge Mode Timing Diagram LDO Mode Timing Diagram CHRGB VCC NTC IOUT VOUT CPB TIMER Pre-Charge UVLO Soft Start 2.8V CC-mode On Fast Charge On On Hold Off On On Off Termination Current Re-Charge Threshold Fault CV- mode CHRGB VCC NTC IOUT VOUT CPB TIMER (Disabled) UVLO Soft Start 2.8V CC-mode Fast Charge CV-mode Off On On Off Termination Current Re-Charge Threshold Fault Load Current Transient

© 2008 Semtech Corporation SC802/SC802A Evaluation Board Schematic 1μF JP1 4.2V 2R2 CHRG JP4 4.1V TP8 RGND JP2 TINT No Pop 3.01k 37.5k CP No Pop 2.2μF 10k JP3 LDO No Pop TP7 ISENSE TP3 EN-NTC TP2 Charger- TP2 Charger+ TP6 AFC TP4 VOUT TP5 GND 100k SC802/SC802A VCC1 BSEN IPRGM EN_NTC ITERM VOUT2 RTIM CHRGB VPRGM CPB RFGND BIPB VCC2 GND VOUT1 AFC

© 2008 Semtech Corporation SC802/SC802A A D .003 .010 .079 .012 .085 .000 .031 (.008) 0.08 0.30 .014 .089 0.25 2.00 .039 .002 0.00 0.80 2.25 0.35 2.15 0.05 1.00 (0.20) .004 0.10 2.00 2.15 2.25 0.65 BSC.026 BSC .089.085.079 SEATING PLANE N CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. NOTES: E B MIN MAX MILLIMETERS MINMAX NOM INDICATOR (LASER MARK) PIN 1 DIMENSIONS NOM INCHES N bbb aaa DIM L e E D A b aaa C A C e/2 LxN E/2 e bxN bbb C A BD/2 Outline Drawing — MLPQ-16 (4×4×0.9mm)

© 2008 Semtech Corporation Semtech Corporation Power Management Products Division

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Phone: (805) 498-2111 Fax: (805) 498-3804 www.semtech.com Contact Information SC802/SC802A Outline Drawing — MLPQ-16 (4×4×0.9mm) C Z P Y X G K H .189 .026 .016 .041 .106 .091 .091 4.80 0.40 1.05 0.65 2.30 2.30 2.70 DIM (3.75) MILLIMETERS DIMENSIONS (.148) INCHES THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR SQUARE PACKAGE - DIMENSIONS APPLY IN BOTH " X " AND " Y " DIRECTIONS. SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FUNCTIONAL PERFORMANCE OF THE DEVICE. (C) G Z P X Y K H THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. NOTES: