MICREL MIC79050-4.2BMM, MIC79050-4.2BS, MIC79050-4.2BM Datasheet

MIC79050 Micrel

4.2V ±0.75%
Li-Ion

Cell

IN BAT

FB

GND

EN

MIC79050-4.2BMM

External PWM*

*See Applications Information

Regulated or

unregulated

wall adapter

MIC79050

Simple Lithium-Ion Battery Charger

Preliminary Information

General Description

The MIC79050 is a simple single-cell lithium-ion battery
charger. It includes an on-chip pass transistor for high preci­sion charging. Featuring ultrahigh precision (+0.75% over the
Li-ion battery charging temperature range) and “zero” off
mode current, the MIC79050 provides a very simple, cost
effective solution for charging lithium-ion battery.

Other features of the MIC79050 include current limit and
thermal shutdown protection. In the event the input voltage to
the charger is disconnected, the MIC79050 also provides
minimal reverse-current and reversed-battery protection.

The MIC79050 is a fixed 4.2V device and comes in the
thermally-enhanced MSO-8, SO-8, and SOT-223 packages.
The 8-pin versions also come equipped with enable and
feedback inputs. All versions are specified over the tempera­ture range of –40°C to +125°C.

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

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 SOP-8, and SOT-223

• Pulse charging capability

Applications

• Li-ion battery charger

• Celluar phones

• Palmtop computers

• PDAs

• Self charging battery packs

Typical Applications

Regulated or

unregulated

wall adapter

MIC79050-4.2BS

IN BAT

GND

Simplest Battery Charging Solution

Pulse-Charging Application

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com

June 2000 1 MIC79050

4.2V ±0.75% Over Temp

Li-Ion
Cell

MIC79050 Micrel

Pin Configuration

GND

TAB

132

IN

GND

BAT

MIC79050-x.xBS

SOT-223

EN

BAT

FB

IN

1
2
3
4

GND

8

GND

7

GND

6

GND

5

MIC79050-x.xBM

SOP-8 and MSOP-8

Pin Description

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 2 June 2000

MIC79050 Micrel

Absolute Maximum Ratings (Note 1)

Supply Input Voltage (V
Power Dissipation (P
Junction Temperature (T

Lead Temperature (soldering, 5 sec.) ....................... 260°C

Storage Temperature (T

) ............................ –20V to +20V

IN

) ............... Internally Limited, Note 3

D

) ....................... –40°C to +125°C

J

) ....................... –65°C to +150°C

S

Operating Ratings (Note 2)

Supply Input Voltage (V
Enable Input Voltage (V

Junction Temperature (TJ) ....................... –40°C to +125°C

Package Thermal Resistance (Note 3) ...............................

MSOP-8 (θ
SOP-8(θ

)......................................................80°C/W

JA

)..........................................................63°C/W

JA

) ........................... +2.5V to +16V

IN

) .................................. 0V to V

EN

SOT-223(θJC)......................................................15°C/W

Electrical Characteristics

VIN = V

Symbol Parameter Conditions Min Typical Max Units

V

BAT

∆V

BAT

∆V

BAT/VBAT

∆V

BAT/VBAT

V

– V

IN

I

GND

I

GND

PSRR Ripple Rejection f = 120Hz 75 dB
I

LIMIT

∆V

BAT

ENABLE Input

V

ENL

I

ENL

I

ENH

BAT

+ 1.0V; C

Battery Voltage Accuracy variation from nominal V

= 4.7µF, I

OUT

= 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.

OUT

–5°C to +60°C –0.75 +0.75 %

OUT

/∆T Battery Voltage Note 4 40 ppm/°C

Temperature Coefficient
Line Regulation VIN = V

+ 1V to 16V 0.009 0.05 %/V

BAT

0.1 %/V

Load Regulation I

= 100µA to 500mA, Note 5 0.05 0.5 %

OUT

0.7 %

BAT

Dropout Voltage, Note 6 I

= 500mA 380 500 mV

OUT

600 mV

Ground Pin Current, Notes 7, 8 VEN ≥ 3.0V, I

= 100µA 85 130 µA

OUT

170 µA

V

≥ 3.0V, I

EN

= 500mA 11 20 mA

OUT

25 mA

Ground Pin Quiescent Current, VEN ≤ 0.4V (shutdown) 0.05 3 µA

Note 8

Current Limit V

VEN ≤ 0.18V (shutdown) 0.10 8 µA

= 0V 750 900 mA

BAT

1000 mA

/∆P

Thermal Regulation Note 9 0.05 %/W

D

Enable Input Logic-Low Voltage VEN = logic low (shutdown) 0.4 V

0.18 V

VEN = logic high (enabled) 2.0 V

Enable Input Current V

≤ 0.4V (shutdown) 0.01 –1 µA

ENL

V

≤ 0.18V (shutdown) 0.01 –2 µA

ENL

V

≥ 2.0V (enabled) 5 20 µA

ENH

25 µA

IN

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: P

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.

D(max)

= (T

– TA) ÷ θJA. Exceeding the

J(max)

June 2000 3 MIC79050

MIC79050 Micrel

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 V

= 16V for t = 10ms.

IN

MIC79050 4 June 2000

MIC79050 Micrel

g

g

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

0

100

200

300

400

500

600

700

800

-40 0 40 80 120

SHORT CIRCUIT CURRENT (mA)

TEMPERATURE (C)

Short Circuit Current

vs. Temperature

Typical Characteristics

Dropout Voltage

vs. Output Current

400

300

200

100

DROPOUT VOLTAGE (mV)

0

0 100 200 300 400 500

OUTPUT CURRENT (mA)

Dropout Characteristics

5

4

3

2

1

OUTPUT VOLTAGE (V)

0

0246

250mA

500mA

INPUT VOLTAGE (V)

Dropout Voltage

600

500

400

300

200

100

DROPOUT VOLTAGE (mV)

vs. Temperature

0

-40 0 40 80 120

TEMPERATURE (C)

Output Current

12

10

8

6

4

2

GROUND CURRENT (mA)

0

0 100 200 300 400 500

vs. Ground

OUTPUT CURRENT (mA)

Dropout Characteristics

5

4

3

2

1

OUTPUT VOLTAGE (V)

5mA

50mA, 150mA

0

0246810121416

INPUT VOLTAGE (V)

Ground Current

vs. Supply Volta

1.5

50mA

1

5mA

0.5

GROUND CURRENT (mA)

0

0 4 8 12 16

SUPPLY VOLTAGE (V)

e

vs. Supply Volta

25

20

15

10

5

GROUND CURRENT (mA)

0

0123456

SUPPLY VOLTAGE (V)

13.5

13.0

12.5

June 2000 5 MIC79050

12.0

11.5

GROUND CURRENT (mA)

11.0

-40 0 40 80 120

Ground Current

500mA

250mA
125mA

Ground Current

vs. Temperature

TEMPERATURE (C)

Ground Current

e

150

100

GROUND CURRENT (uA)

vs. Temperature

50

0

-40 0 40 80 120

TEMPERATURE (C)

Battery Voltage

4.210

4.205

4.200

4.195

OUTPUT VOLTAGE (V)

4.190

vs. Temperature

-40 -20 0 20 40 60 80 100120140

TEMPERATURE (C)

MIC79050 Micrel

Typical Voltage Drift Limits

0.75

0.25

-0.25

-0.75

DRIFT FROM NOMINAL VOUT (%)

0 200 400 600 800

vs. Time

Upper

Lower

TIME (hrs)

Reverse Leakage Current

vs. Output Voltage

20

15

10

5

0

012345

REVERSE LEAKAGE CURRENT (µA)

OUTPUT VOLTAGE (V)

Reverse Leakage Current

vs. Temperature

20

4.2V

15

3.6V

10

3.0V

5

0

-5 5 1525354555

REVERSE LEAKAGE CURRENT (uA)

TEMPERATURE (C)

VIN+V

EN

GROUNDED

Reverse Leakage Current

vs. Output Voltage

20

4.2V

15

3.6V

10

3.0V

5

0

-5 5 1525354555

REVERSE LEAKAGE CURRENT (µA)

TEMPERATURE (C)

VIN+V

EN

FLOATING

MIC79050 6 June 2000