MIC79050_05 MICREL | Alldatasheet

Document overview

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Technical content

Features

  • High accuracy charge voltage: ±0.75% over -5°C to + 60°C (Li-ion charging temperature range)
  • “Zero” off-mode current
  • 10µA 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 SOIC-8, and SOT-223
  • Pulse charging capability

Applications

  • Li-ion battery charger
  • Celluar phones
  • Palmtop computers
  • PDAs
  • Self charging battery packs Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

Ordering Information

Temp. Range PackageStandard Pb-Free MIC79050-4.2BS MIC79050-4.2YS 4.2V –40ºC to +125ºC SOT-223-3 MIC79050-4.2BM MIC79050-4.2YM 4.2V –40ºC to +125ºC SOIC-8 MIC79050-4.2BMM MIC79050-4.2YMM 4.2V –40ºC to +125ºC MSOP-8

MIC79050 Micrel, Inc. MIC79050 2 August 2005 Pin Description Pin No. Pin No. Pin Name Pin Function SOT-223 SOIC-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

Pin Configuration IN BATGND 1 32 TAB GND MIC79050-x.xBS/YS SOT-223 GND GND GND GND EN IN BAT FB MIC79050-x.xBM/YM SOIC-8 and MSOP-8

MIC79050 Micrel, Inc.

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 VOUT –5°C to +60°C –0.75 +0.75 % ΔVBAT/ΔT Battery Voltage Note 4 40 ppm/°C Temperature Coefficient ΔVBAT/VBAT Line Regulation VIN = VBAT + 1V to 16V 0.009 0.05 %/V 0.1 %/V ΔVBAT/VBAT Load Regulation IOUT = 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 V EN ≥ 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 VBAT = 0V 750 900 mA 1000 mA ΔVBAT/ΔPD Thermal Regulation Note 9 0.05 %/W ENABLE Input VENL Enable Input Logic-Low Voltage V EN = logic low (shutdown) 0.4 V 0.18 V VEN = logic high (enabled) 2.0 V IENL Enable Input Current VENL ≤ 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 T A (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. Note 8: V EN 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. Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2)

MIC79050 Micrel, Inc. MIC79050 4 August 2005 Typical Characteristics 100 200 300 400 0 100 200 300 400 500 DROPOUT VOLTAGE (mV) OUTPUT CURRENT (mA) Dropout Voltage vs. Output Current 100 200 300 400 500 600 -40 0 4 0 8 0 120 DROPOUT VOLTAGE (mV) TEMPERATURE (°C) Dropout Voltage vs. Temperature 0 2 4 6 8 1 0 1 2 1 4 1 6 OUTPUT VOLTAGE (V) INPUT VOLTAGE (V) Dropout Characteristics 50mA, 150mA 5mA 0 2 4 6 OUTPUT 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 0 1 2 3 4 5 6 GROUND CURRENT (mA) SUPPLY VOLTAGE (V) Ground Current vs. Supply Voltage 500mA 250mA 125mA 100 150 -40 0 4 0 8 0 120 GROUND CURRENT (µA) TEMPERATURE (°C) Ground Current vs. Temperature 3.0 3.2 3.4 3.6 3.8 4.0 -40 0 4 0 8 0 120 GROUND CURRENT (mA) TEMPERATURE (°C) Ground Current vs. Temperature 11.0 11.5 12.0 12.5 13.0 13.5 -40 0 4 0 8 0 120 GROUND CURRENT (mA) TEMPERATURE (°C) Ground Current vs. Temperature 4.190 4.195 4.200 4.205 4.210 -40 -20 0 2 0 40 60 80 100120140 OUTPUT VOLTAGE (V) TEMPERATURE (°C) Battery Voltage vs. Temperature 100 200 300 400 500 600 700 800 -40 0 4 0 8 0 120 SHORT CIRCUIT CURRENT (mA) TEMPERATURE (°C) Short Circuit Current vs. Temperature

MIC79050 Micrel, Inc. -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 0 1 2 3 4 5 REVERSE LEAKAGE CURRENT (µA)OUTPUT VOLTAGE (V) Reverse Leakage Current vs. Output Voltage -5 5 1 5 2 5 3 5 4 5 5 5 REVERSE LEAKAGE CURRENT (µA)TEMPERATURE (°C) Reverse Leakage Current vs. Output Voltage 3.0V 3.6V 4.2V VIN+VE N FLOATING -5 5 1 5 2 5 3 5 4 5 5 5 REVERSE LEAKAGE CURRENT (uA) TEMPERATURE (°C) Reverse Leakage Current vs. Temperature 3.0V 3.6V 4.2V VIN+VE N GROUNDED

MIC79050 Micrel, Inc. MIC79050 6 August 2005 Block Diagrams Current Limit Thermal Shutdown IN GND Bandgap Ref. VBAT VIN MIC79050-x.xBS 3-Pin Version Functional Description 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 ac curate termination 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 volt age charging 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 typi cally 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 am plifier. This amplifier compares the voltage at the feedback 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 controlling the voltage at the feedback pin the output can be disabled or forced to the input voltage. Pulling and holding the feedback 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. IN EN FB GND VR E F Bandgap Ref. Current Limit Thermal Shutdown VBAT VIN MIC79050-x.xBMM/M 5-Pin Version

79050 Programmed

Figure 2. Protected Constant-Current Charger

  1. State A: Initial charge. Here the battery’s charging cur-

rent is limited by the wall adapter’s natural impedance. The battery voltage approaches 4.2V.

  1. State B: Constant voltage charge. Here the battery

battery is low, indicating full charge.

  1. State C: End of charge cycle. When the input voltage,

VS reaches VEOC, an end of charge signal is indicated.

  1. State D: Top up charge. As soon as enough current

pulled low and charging will initiate.

MIC79050 Micrel, Inc.

Package Information

SOT-223 (S) 8-Pin SOIC (M)

MIC79050 Micrel, Inc. MIC79050 14 August 2005 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 (0.3) 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. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2000 Micrel, Inc.