MIC79050 MICREL | Alldatasheet
Document overview
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- PDF pages: 20
Technical content
Features
- High accuracy charge voltage: ±0.75% over -5°C to + 60°C (Li-ion charging temperature range)
- “Zero” off-mode current
- 1 0µA reverse leakage
- Ultralow 380mV dropout at 500mA
- Wide input voltage range
- Logic controlled enable input (8-pin devices only)
- Thermal shutdown and current limit protection
- Power MSOP-8, Power SOP-8, and SOT-223
- Pulse charging capability
Applications
- Li-ion battery charger
- Celluar phones
- Palmtop computers
- PDAs
- Self charging battery packs Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
Ordering Information
Part Number Voltage Junct. Temp. Range Package MIC79050-4.2BS 4.2V –40 °C to +125°C SOT-223 MIC79050-4.2BM 4.2V –40 °C to +125°C SOP-8 MIC79050-4.2BMM 4.2V –40 °C to +125°C MSOP-8
Pin No. Pin No. Pin Name Pin Function SOT-223 SOP-8 MSOP-8 1 2 IN Supply Input 2, TAB 5–8 GND Ground: SOT-223 pin 2 and TAB are internally connected. SO-8 pins 5 through 8 are internally connected. 3 3 BAT Battery Voltage Output 1 EN Enable (Input): TTL/CMOS compatible control input. Logic high = enable; logic low or open = shutdown.
4 FB Feedback Node
MIC79050-x.xBS SOT-223 GND GND GND GND EN IN BAT FB MIC79050-x.xBM SOP-8 and MSOP-8
Electrical Characteristics
VIN = VBAT + 1.0V; COUT = 4.7µF, IOUT = 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted. Symbol Parameter Conditions Min Typical Max Units VBAT Battery Voltage Accuracy variation from nominal V OUT –5°C to +60°C –0.75 +0.75 % ∆VBAT /∆T Battery Voltage Note 4 40 ppm/°C Temperature Coefficient ∆VBAT /VBAT Line Regulation V IN = VBAT + 1V to 16V 0.009 0.05 %/V 0.1 %/V ∆VBAT /VBAT Load Regulation I OUT = 100µA to 500mA, Note 5 0.05 0.5 % 0.7 % VIN – VBAT Dropout Voltage, Note 6 IOUT = 500mA 380 500 mV 600 mV IGND Ground Pin Current, Notes 7, 8 VEN ≥ 3.0V, IOUT = 100µA 85 130 µA 170 µA VEN ≥ 3.0V, IOUT = 500mA 11 20 mA 25 mA IGND Ground Pin Quiescent Current, V EN ≤ 0.4V (shutdown) 0.05 3 µA Note 8 VEN ≤ 0.18V (shutdown) 0.10 8 µA PSRR Ripple Rejection f = 120Hz 75 dB ILIMIT Current Limit V BAT = 0V 750 900 mA 1000 mA ∆VBAT /∆PD Thermal Regulation Note 9 0.05 %/W ENABLE Input VENL Enable Input Logic-Low Voltage VEN = logic low (shutdown) 0.4 V 0.18 V VEN = logic high (enabled) 2.0 V IENL Enable Input Current V ENL ≤ 0.4V (shutdown) 0.01 –1 µA VENL ≤ 0.18V (shutdown) 0.01 –2 µA IENH VENH ≥ 2.0V (enabled) 5 20 µA 25 µA Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. The maximum allowable power dissipation at any TA (ambient temperature) is calculated using: PD(max) = (TJ(max)– TA) ÷ θJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. Note 4. Battery voltage temperature coefficient is the worst case voltage change divided by the total temperature range. Note 5. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range from 100µA to 500mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification. Note 6. Dropout voltage is defined as the input to battery output differential at which the battery voltage drops 2% below its nominal value measured at 1V differential. Note 7: Ground pin current is the charger quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load current plus the ground pin current. Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2)
Note 8: VEN is the voltage externally applied to devices with the EN (enable) input pin. [MSO-8(MM) and SO-8 (M) packages only.] Note 9: Thermal regulation is the change in battery voltage at a time “t” after a change in power dissipation is applied, excluding load or line regulation effects. Specifications are for a 500mA load pulse at VIN = 16V for t = 10ms.
DROPOUT VOLTAGE (mV) OUTPUT CURRENT (mA) Dropout Voltage vs. Output Current 100 200 300 400 500 600 -40 0 40 80 120 DROPOUT VOLTAGE (mV) TEMPERATURE (C) Dropout Voltage vs. Temperature 02468 1 0 1 2 1 4 1 6OUTPUT VOLTAGE (V) INPUT VOLTAGE (V) Dropout Characteristics 50mA, 150mA 5mA 0246OUTPUT VOLTAGE (V) INPUT VOLTAGE (V) Dropout Characteristics 250mA 500mA 0 100 200 300 400 500 GROUND CURRENT (mA) OUTPUT CURRENT (mA) Output Current vs. Ground 0.5 1.5 0 4 8 12 16 GROUND CURRENT (mA) SUPPLY VOLTAGE (V) Ground Current vs. Supply Voltage 50mA 5mA 0123456 GROUND CURRENT (mA) SUPPLY VOLTAGE (V) Ground Current vs. Supply Voltage 500mA 250mA 125mA 100 150 -40 0 40 80 120 GROUND CURRENT (uA) TEMPERATURE (C) Ground Current vs. Temperature 3.0 3.2 3.4 3.6 3.8 4.0 -40 0 40 80 120 GROUND CURRENT (mA) TEMPERATURE (C) Ground Current vs. Temperature 11.0 11.5 12.0 12.5 13.0 13.5 -40 0 40 80 120 GROUND CURRENT (mA) TEMPERATURE (C) Ground Current vs. Temperature 4.190 4.195 4.200 4.205 4.210 -40 -20 0 20 40 60 80 100120140 OUTPUT VOLTAGE (V) TEMPERATURE (C) Battery Voltage vs. Temperature 100 200 300 400 500 600 700 800 -40 0 40 80 120 SHORT CIRCUIT CURRENT (mA) TEMPERATURE (C) Short Circuit Current vs. Temperature
-0.75 -0.25 0.25 0.75 0 200 400 600 800 DRIFT FROM NOMINAL VOUT (%) TIME (hrs) Typical Voltage Drift Limits vs. Time Upper Lower 012345 REVERSE LEAKAGE CURRENT ( µA) OUTPUT VOLTAGE (V) Reverse Leakage Current vs. Output Voltage - 5 5 1 52 53 54 55 5 REVERSE LEAKAGE CURRENT ( µA) TEMPERATURE (C) Reverse Leakage Current vs. Output Voltage 3.0V 3.6V 4.2V VIN+VEN FLOATING - 5 5 1 52 53 54 55 5 REVERSE LEAKAGE CURRENT (uA) TEMPERATURE (C) Reverse Leakage Current vs. Temperature 3.0V 3.6V 4.2V VIN+VEN GROUNDED
Ref. VBAT VIN MIC79050-x.xBS 3-Pin Version IN EN FB GND VREF Bandgap Ref. Current Limit Thermal Shutdown VBAT VIN MIC79050-x.xBMM/M 5-Pin Version
The MIC79050 is a high-accuracy, linear battery charging circuit designed for the simplest implementation of a single lithium-ion (Li-ion) battery charger. The part can operate from a regulated or unregulated power source, making it ideal for various applications. The MIC79050 can take an unregulated voltage source and provide an extremely accurate termina- tion voltage. The output voltage varies only 0.75% from nominal over the standard temperature range for Li-ion battery charging (–5°C to 60°C). With a minimum of external components, an accurate constant current charger can be designed to provide constant current, constant voltage charg- ing for Li-ion cells. Input Voltage The MIC79050 can operate with an input voltage up to 16V (20V absolute maximum), ideal for applications where the input voltage can float high, such as an unregulated wall adapter that obeys a load-line. Higher voltages can be sustained without any performance degradation to the output voltage. The line regulation of the device is typically 0.009%/V; that is, a 10V change on the input voltage corresponds to a 0.09% change in output voltage. Enable The MIC79050 has an enable pin that allows the charger to be disabled when the battery is fully charged and the current drawn by the battery has approached a minimum and/or the maximum charging time has timed out. When disabled, the regulator output sinks a minimum of current with the battery voltage applied directly onto the output. This current is typically 12µA or less. Feedback The feedback pin allows for external manipulation of the control loop. This node is connected to an external resistive divider network, which is connected to the internal error amplifier. This amplifier compares the voltage at the feed- back pin to an internal voltage reference. The loop then corrects for changes in load current or input voltage by monitoring the output voltage and linearly controlling the drive to the large, PNP pass element. By externally control- ling the voltage at the feedback pin the output can be disabled or forced to the input voltage. Pulling and holding the feed- back pin low forces the output low. Holding the feedback pin high forces the pass element into saturation, where the output will be the input minus the saturation (dropout) voltage. Battery Output The BAT pin is the output of the MIC79050 and connects directly to the cell to provide charging current and voltage. When the input is left floating or grounded, the BAT pin limits reverse current to <12µA to minimize battery drain.
Battery Current (IB) Battery Voltage (VB) Unregulated Input Voltage(VB)
79050 Programmed
(No Load Voltage) End of Charge (VEOC ) State A Initial Charge State B Voltage Charge State C End of Charge State D Charge Top State C Figure 1C. Charging Cycles
Application Information
MIC79050-4.2BM LM4041 CIM3-1.2 5V ±5%@ 400mA ±5% 4.7µF 8.06M 47k 47k 0.050Ω 10k MIC6270 MIC7300 10k1k Figure 2. Protected Constant-Current Charger
- State A: Initial charge. Here the battery’s charging
ance. The battery voltage approaches 4.2V.
- State B: Constant voltage charge. Here the battery
the battery is low, indicating full charge.
- State C: End of charge cycle. When the input voltage,
S reaches VEOC, an end of charge signal is indicated.
- State D: Top up charge. As soon as enough current is
pulled low and charging will initiate.
Package Information
16° 10° 0.84 (0.033) 0.64 (0.025) 1.04 (0.041) 0.85 (0.033) 2.41 (0.095) 2.21 (0.087) 4.7 (0.185) 4.5 (0.177) 6.70 (0.264) 6.30 (0.248) 7.49 (0.295) 6.71 (0.264) 3.71 (0.146) 3.30 (0.130) 3.15 (0.124) 2.90 (0.114) 10° MAX 0.10 (0.004) 0.02 (0.0008) 0.38 (0.015) 0.25 (0.010) CL DIMENSIONS: MM (INCH) CL 1.70 (0.067) 1.52 (0.060) 0.91 (0.036) MIN SOT-223 (S) 45° 0°–8° 0.244 (6.20) 0.228 (5.79) 0.197 (5.0) 0.189 (4.8) SEATING PLANE 0.026 (0.65) MAX ) 0.010 (0.25) 0.007 (0.18) 0.064 (1.63) 0.045 (1.14) 0.0098 (0.249) 0.0040 (0.102) 0.020 (0.51) 0.013 (0.33) 0.157 (3.99) TYP PIN 1 DIMENSIONS: INCHES (MM) 0.050 (1.27) 0.016 (0.40) 8-Pin SOP (M)
0.008 (0.20) 0.004 (0.10) 0.039 (0.99) 0.035 (0.89) 0.021 (0.53) 0.012 (0.03) R 0.0256 (0.65) TYP 0.012 (0.30) R 5° MAX 0° MIN 0.122 (3.10) 0.112 (2.84) 0.120 (3.05) 0.116 (2.95) 0.012 (0.03) 0.007 (0.18) 0.005 (0.13) 0.043 (1.09) 0.038 (0.97) 0.036 (0.90) 0.032 (0.81) DIMENSIONS: INCH (MM) 0.199 (5.05) 0.187 (4.74) 8-Pin MSOP (MM)
MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. © 2000 Micrel Incorporated