19-0614; Rev 0; 8/06

Battery Power-Up Logic with Overvoltage and Overcurrent Protection Features

The MAX4919B/MAX4920B/MAX4921B overvoltage protection controllers protect low-voltage systems against high-voltage faults up to +28V. An internal 1.8A (min) pFET with low RON (100mΩ) switches a battery to the load and also protects the battery against short-circuit faults. When a short circuit occurs, the current through the internal pFET is limited for a blanking period. If the short condition is present after the blanking period, the switch is latched off and remains off until one of the input signals (IN, HP_PWR, PWR_ON) is cycled. The pFET is turned on by a logic-high voltage at PWR_HOLD, HP_PWR, PWR_ON, or IN .

♦ Input Overvoltage Protection Up to +28V

The overvoltage thresholds (OVLO) are preset to +6.38V (MAX4919B), +5.80V (MAX4920B), and +4.65V (MAX4921B). When the input voltage drops below the undervoltage lockout (UVLO) threshold, the devices enter a low-current standby mode. In shutdown mode, the current is reduced to 0.4µA. The MAX4919B/MAX4920B have a +4.27V UVLO threshold, and the MAX4921B has a +2.35V UVLO threshold. The MAX4919B/MAX4920B/MAX4921B are offered in a small 14-pin TDFN package (3mm x 3mm) with an exposed paddle and are specified over the extended -40°C to +85°C temperature range.

♦ Battery Short-Circuit Protection

♦ Preset Overvoltage Protection Trip Level 6.38V (MAX4919B) 5.80V (MAX4920B) 4.65V (MAX4921B) ♦ Adapter/Car-Kit Auto-Selector ♦ Low-Current Undervoltage Lockout Mode ♦ Internal 1.8A (min) Battery Switchover FET ♦ Integrated Low-Battery Detect ♦ Low-Cost External nMOS Overvoltage FET ♦ 14-Pin TDFN Package (3mm x 3mm)

EN

ACOK

PWR_HOLD

BTO

BTO

ONOK

GND

Pin Configuration

14

13

12

11

10

9

8

TOP VIEW

Applications Cell Phones

MAX4919B MAX4920B MAX4921B

Digital Still Cameras

4

5

6

7 PWR_ON

IN

3

HP_PWR

2

BTI

1 GP1

*EP

BTI

+

MP3 Players

GN1

PDAs and Palmtop Devices

TDFN (3mm x 3mm) *EXPOSED PADDLE +DENOTES LEAD-FREE PACKAGE

Ordering Information/Selector Guide PART

PINPACKAGE

OVLO (V)

UVLO (V)

TOP MARK

PKG CODE

MAX4919BETD+T

14 TDFN-EP*

6.38

4.27

ABY

T1433-2

MAX4920BETD+T

14 TDFN-EP*

5.80

4.27

ABZ

T1433-2

MAX4921BETD+T

14 TDFN-EP*

4.65

2.35

ACA

T1433-2

Note: All devices are specified over the -40°C to +85°C operating temperature range. +Denotes lead-free package. *EP = Exposed paddle. ________________________________________________________________ Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

1

MAX4919B/MAX4920B/MAX4921B

General Description

MAX4919B/MAX4920B/MAX4921B

Battery Power-Up Logic with Overvoltage and Overcurrent Protection ABSOLUTE MAXIMUM RATINGS IN to GND ...............................................................-0.3V to +30V GP1, GN1 to GND ..................................................-0.3V to +12V IN to GP1 ................................................................-0.3V to +20V BTO to GND ..........................................................-0.3V to +6.1V BTI to BTO ................................................................-0.3V to +6V BTI, ACOK, PWR_ON, EN to GND ...........................-0.3V to +6V HP_PWR, ONOK, PWR_HOLD to GND ....................-0.3V to +6V

Continuous Power Dissipation (TA = +70°C) 14-Pin TDFN (derate 18.5mW/°C above +70°C) .......1482mW Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS (VIN = 5V (MAX4919B/MAX4920B) or VIN = 4.2V (MAX4921B), VBTI = 4V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER Input Voltage Range

SYMBOL

Input Supply Current

IIN

UVLO Supply Current

IUVL

Shutdown Supply Current IN Undervoltage Lockout

CONDITIONS

VIN

ISHDN VUVLO

MIN

MAX

UNITS

28

V

MAX4919B/MAX4920B

77

120

MAX4921B

75

110

VEN = 0V; VIN = 3.9V; MAX4919B/MAX4920B

10

22

VEN = 0V; VIN = 2.1V; MAX4921B

8

18

VEN = 1.6V, VIN = 3.6V VIN falling

VIN rising

µA

0.4

2

µA

4.00

4.27

4.54

V

MAX4921B

2.20

2.35

2.50

V

1

VOVLO

µA

MAX4919B/MAX4920B

IN Undervoltage Lockout Hysteresis Overvoltage Trip Level

TYP

1.2

%

MAX4919B

6.00

6.38

6.76

MAX4920B

5.44

5.80

6.17

MAX4921B

4.35

4.65

4.95

IN Overvoltage Lockout Hysteresis

1

V

%

BATTERY SWITCHOVER BTI Input Range BTI UVLO

VBTI VUVBTI

2.30 VBTI falling

2.0

BTI UVLO Hysteresis BTI Low-Battery Threshold

5.50 2.15

2.3

1.5 VLVBTI

VBTI falling

2.65

BTI Low-Battery Hysteresis

2.82

Adapter out, VPWR_HOLD = high, EN = high

BTI Shutdown Current

VBTO = 0V

3

2

TA = -40°C to +85°C

V %

7

TA = +25°C

V %

1.5

BTI Supply Current

V

2.8

µA µA

INTERNAL pFET Switch On-Resistance

RON

VBTI = 2.7V, IBTI to BTO = 0.5A

Forward-Overload Current Limit

ILIM

BTO shorted to GND

2

TA = +25°C

100

TA = -40°C to +85°C

120 1.8

_______________________________________________________________________________________

mΩ A

Battery Power-Up Logic with Overvoltage and Overcurrent Protection (VIN = 5V (MAX4919B/MAX4920B) or VIN = 4.2V (MAX4921B), VBTI = 4V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

VGN1 referenced to GND, IGN1 sourcing 1µA; MAX4919B/MAX4920B

9

10

VGN1 referenced to GND, IGN1 sourcing 1µA; MAX4921B

7.8

8.4

UNITS

GATE DRIVERS

GN1 Turn-On Voltage

GN1 Pulldown Current GP1 Clamp Voltage GP1 Pulldown Resistor

VGN1

IGPD

VIN > OVLO, VGN1 = 5.5V

VCLAMP

VIN - VGP1 when VIN = 28V

RGPD

V

30

mA

12.5

16.5

19.5

V

31

51.5

72

kΩ

LOGIC INPUTS (PWR_HOLD, HP_PWR, PWR_ON, EN) Input-High Voltage Input-Low Voltage

VIH

VBTI = 5.50V

VIL

VBTI = 2.3V for PWR_HOLD, HP_PWR and EN; VBTI = 3V for PWR_ON

PWR_HOLD, EN Input Leakage Current

ILKG

PWR_ON, HP_PWR Pulldown Resistance

RIPD

EN, PWR_HOLD = GND or 5.5V

1.5

V

-1

0.4

V

+1

µA

200

kΩ

LOGIC OUTPUTS (ACOK, ONOK) Output-Low Voltage

VOL

ISINK = 1mA

Output-High Leakage Current

0.4

V

1

µA

TIMING IN Debounce Time

tINDBC

Time from UVLO < VIN < OVLO to VGN1 > 0.3V, CGN1 = 500pF

10

25

40

ms

ACOK Blanking Time

tBLNKAC

Time from VGN1 > 0.3V to ACOK low, CGN1 = 500pF

10

25

40

ms

HP_PWR Debounce Time

tHPDBC

Time for internal pFET to turn on after VHP_PWR > VIH

10

25

40

ms

ACOK One-Shot Time

t1SHAC

VPWR_HOLD = 0V; time for internal pFET to turn off after ACOK < VOL (Figure 1)

488

1220

1952

ms

HP_PWR One-Shot Time

t1SHHP

VPWR_HOLD = 0V; time for internal pFET to turn off after VHP_PWR > VIH (Figure 2)

488

1220

1952

ms

tCLIM

VBTI = 2.7V; VBTO shorted to GND; time for internal pFET current to reduce to 10mA

4

10

16

ms

tGON

VGN1 = 0.3V to 8V (MAX4919B/MAX4920B), VGN1 = 0.3V to 7V (MAX4921B), CGN1 = 500pF

Current-Limit Blanking Time

GN1 Turn-On Time

10

ms

_______________________________________________________________________________________

3

MAX4919B/MAX4920B/MAX4921B

ELECTRICAL CHARACTERISTICS (continued)

ELECTRICAL CHARACTERISTICS (continued) (VIN = 5V (MAX4919B/MAX4920B) or VIN = 4.2V (MAX4921B), VBTI = 4V, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

6

20

µs

GN1 Turn-Off Time

tGOFF

VIN rising at 1V/µs from 5V to 8V (MAX4919B/MAX4920B), or from 4V to 7V (MAX4921B); VGN1 = 0.3V, CGN1 = 500pF

Initial Overvoltage Fault Delay

tOVLO

VIN rising at 1V/µs from 0V to 9V, time from VIN = 5V to IGN1 = 80% of IGPD

1.5

µs

tACOK

VIN rising at 1V/µs from 5V to 8V (MAX4919B/MAX4920B), or from 4V to 7V (MAX4921B); VACOK pullup voltage = 3V; RACOK = 10kΩ (Figure 3)

5.8

µs

tDIS

VEN = 2.4V, VGN1 = 0.3V, CGN1 = 500pF

2

µs

ACOK Deassertion Delay

Disable Time

Note 1: All specifications are 100% production tested at TA = +25°C, unless otherwise noted. Specifications over TA = -40°C to +85°C are guaranteed by design.

Typical Operating Characteristics (VBTI = 4V, TA = +25°C, unless otherwise noted.)

10 8 6 4

8 6 4 2

0

0 3

4

5

INPUT VOLTAGE (V)

6

7

MAX4921B VGN1 REFERENCED TO GND

10

2

2

4

12

MAX4919/20/21B toc02

12

14

1.5 NORMALIZED BATTERY SWITCH RON

MAX4919B VGN1 REFERENCED TO GND

GN1 GATE VOLTAGE (V)

MAX4919/20/21B toc01

14

NORMALIZED BATTERY SWITCH RON vs. TEMPERATURE

GN1 GATE VOLTAGE vs. INPUT VOLTAGE

MAX4919/20/21B toc03

GN1 GATE VOLTAGE vs. INPUT VOLTAGE

GN1 GATE VOLTAGE (V)

MAX4919B/MAX4920B/MAX4921B

Battery Power-Up Logic with Overvoltage and Overcurrent Protection

1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5

2.0

2.5

3.0

3.5

4.0

INPUT VOLTAGE (V)

4.5

5.0

-40

-15

10

35

TEMPERATURE (°C)

_______________________________________________________________________________________

60

85

Battery Power-Up Logic with Overvoltage and Overcurrent Protection

NORMALIZED OVLO THRESHOLD vs. TEMPERATURE

CURRENT LIMIT vs. TEMPERATURE

CURRENT LIMIT (A)

3.6 3.4 3.2 3.0 2.8 2.6 2.4

1.015 1.010 1.005 1.000 0.995 0.990 0.985

2.2

0.980

2.0 -40

-15

10

35

60

85

-40

-15

10

35

60

85

TEMPERATURE (°C)

TEMPERATURE (°C)

NORMALIZED UVLO THRESHOLD vs. TEMPERATURE

ADAPTER POWER-UP RESPONSE MAX4919/20/21B toc07 MAX4919/20/21B toc06

1.020 NORMALIZED UVLO THRESHOLD

1.020

MAX4919/20/21B toc05

3.8

NORMALIZED OVLO THRESHOLD

MAX4919/20/21B toc04

4.0

1.015 1.010

MAX4919B

VADAPTER (5V/div) VIN (5V/div) VGN1 (5V/div)

1.005 1.000 0.995

VACOK (5V/div)

0.990 0.985

VOUT (5V/div)

0.980 -40

-15

10

35

60

10ms/div

85

TEMPERATURE (°C)

ADAPTER POWER-UP RESPONSE

OVERVOLTAGE RESPONSE

MAX4919/20/21B toc08

MAX4919B

MAX4919/20/21B toc09

VADAPTER (5V/div)

MAX4919B 7V VADAPTER (2V/div) 5V

VIN (5V/div) VGN1 (5V/div)

7V V IN (2V/div) 5V

PWR_ON, HP_PWR, PWR_HOLD = 0V

200ms/div

VACOK (5V/div)

VGN1 (5V/div)

VBTO (5V/div)

VACOK (5V/div) 2µs/div

_______________________________________________________________________________________

5

MAX4919B/MAX4920B/MAX4921B

Typical Operating Characteristics (continued) (VBTI = 4V, TA = +25°C, unless otherwise noted.)

MAX4919B/MAX4920B/MAX4921B

Battery Power-Up Logic with Overvoltage and Overcurrent Protection Typical Operating Characteristics (continued) (VBTI = 4V, TA = +25°C, unless otherwise noted.) BATTERY-SWITCH TURN-ON RESPONSE (PWR_ON RISING)

UNDERVOLTAGE RESPONSE

MAX4919/20/21B toc11

MAX4919/20/21B toc10

MAX4919B 5V VADAPTER (2V/div) 3V

CBTI = CBTO = 0.1µF

VONK (5V/div)

5V V IN (2V/div) 3V

VBTI (2V/div)

VGN1 (5V/div)

IBTI (500mA/div)

VACOK (5V/div) 1µs/div

1ms/div

BATTERY-SWITCH TURN-OFF RESPONSE (PWR_ON FALLING)

BATTERY-SWITCH TURN-ON RESPONSE (HP_PWR RISING) MAX4919/20/21B toc13

MAX4919/20/21B toc12

CBTI = CBTO = 0.1µF

VPWR_ON (5V/div)

CBTI = CBTO = 0.1µF

VBTO (2V/div)

VBTO (2V/div)

IBTO (500mA/div)

IBTO (500mA/div)

1ms/div

200ms/div

SHORT-CIRCUIT RESPONSE

BATTERY SWITCH TURN-ON RESPONSE (PWR_ON AND PWR_HOLD RISING) MAX4919/20/21B toc15

MAX4919/20/21B toc14

2ms/div

6

VHP_PWR (5V/div) VBTI (2V/div)

VONOK (5V/div)

CBTI = 47µF CBTO = 0.1µF

VPWR_ON (5V/div)

PWR_ON (5V/div)

VBTI (2V/div)

PWR_HOLD (5V/div)

VBTO (2V/div)

VBTO (2V/div)

IBTO (10A/div)

IBTO (500mA/div) 400ms/div

_______________________________________________________________________________________

Battery Power-Up Logic with Overvoltage and Overcurrent Protection PIN

NAME

FUNCTION

1

GP1

p-Channel MOSFET Gate-Drive Output. GP1 pulls the external pFET gate down when the input is above ground.

2

IN

Voltage Input. IN powers the charge pump required to turn on GN1. When the correct adapter is plugged in, a one-shot turns on the internal pFET for 1.2s, allowing time for the microprocessor (µP) to power-up and drive PWR_HOLD high. Bypass IN with a minimum 1µF ceramic capacitor as close as possible to the device for ±15kV ESD protection. When operating the MAX4919B/MAX4920B/MAX4921B with an external pFET at GP1, place the 1µF capacitor to GND as close to the drain of the pFET as possible for the ±15kV ESD protection. If ±15kV ESD protection is not required, place a minimum 0.1µF capacitor at IN to GND.

3

GN1

n-Channel MOSFET Gate-Drive Output. GN1 is the output of an on-chip charge pump. When VUVLO < VIN < VOVLO, GN1 is driven above the source voltage to turn on the external n-channel MOSFET.

4, 5

BTI

6

HP_PWR

Car-Kit Detection Input. When a car kit is plugged into HP_PWR, a one-shot turns on the internal pFET for 1.2s, allowing time for the µP to power-up and drive PWR_HOLD high.

7

PWR_ON

Power-On Input. Drive PWR_ON high to turn on the internal pFET. The inverse of the PWR_ON logic state is represented at the ONOK logic output.

8

GND

9

ONOK

10, 11

BTO

12

Battery Switch Input. BTI powers the internal circuitry. Bypass BTI with a 0.1µF capacitor. Both BTI inputs must be externally connected together.

Ground Open-Drain PWR_ON Indicator Output. ONOK is a logic output with the inverse state of the PWR_ON input. Battery Switch Output. Both BTO outputs must be externally connected together.

PWR_HOLD Power-Hold Input. Drive PWR_HOLD high to turn on internal pFET. Open-Drain Adapter Voltage Indicator Output. ACOK pulls low when the adapter voltage is stable between UVLO and OVLO for 25ms. Connect a pullup resistor from ACOK to a logic supply.

13

ACOK

14

EN

Enable Input. Drive EN low for normal operation. Drive EN high to turn off the external MOSFETs and enter shutdown mode.

EP

—

Exposed Paddle. Connect EP to ground.

Detailed Description Undervoltage Lockout (UVLO) The MAX4919B/MAX4920B have a 4.27V (typ) undervoltage threshold (UVLO), while the MAX4921B has 2.35V (typ) UVLO threshold. When V IN is less than UVLO, GN1 is held low and ACOK is high impedance.

Overvoltage Lockout Thresholds (OVLO) The MAX4919B has a 6.38V (typ) overvoltage threshold (OVLO), the MAX4920B has a 5.8V (typ) typical OVLO, and the MAX4921B has a 4.65V (typ) OVLO. When VIN is greater than OVLO, GN1 is held low and ACOK is high impedance.

Powering the MAX4919B/ MAX4920B/MAX4921B BTI powers the MAX4919B/MAX4920B/MAX4921B internal circuitry. BTI also connects internally to a 1.8A (min) pFET that conducts an external load to the battery using the BTO output. See the Battery Switchover section.

GP1 Driver When the input voltage goes above ground, GP1 pulls low and turns on the pFET. An internal clamp protects the pFET by insuring that the GP1 to IN voltage does not exceed 19.5V when the input (IN) rises to 28V.

_______________________________________________________________________________________

7

MAX4919B/MAX4920B/MAX4921B

Pin Description

MAX4919B/MAX4920B/MAX4921B

Battery Power-Up Logic with Overvoltage and Overcurrent Protection

ADAPTER VOLTAGE

OVLO UVLO IN 25ms DEBOUNCE PERIOD ACOK

t1SHAC

ACOK ONE-SHOT P2 STATUS

OFF

OFF

ON

Figure 1. ACOK One-Shot Timing Diagram

GN1 Driver An internal 5.5V supply powers the on-chip charge pump used to drive GN1 above IN, allowing the use of a low-cost nFET. The GN1 voltage is approximately two times VIN until VIN exceeds 5.5V, at which point, GN1 clamps to 9.5V (MAX4919B/MAX4920B) or 8.1V (MAX4921B).

ACOK ACOK is an active-low open-drain output that asserts when V UVLO