Rainbow Electronics MAX4880 User Manual

General Description

The MAX4880 is an overvoltage-protection controller
with an internal current-limited switch that can be con­figured as a low-cost battery charger. When the input
voltage exceeds the overvoltage trip level (5.7V), or
drops below the undervoltage-lockout level (4.2V), the
MAX4880 turns off the external n-channel MOSFET and
asserts an undervoltage/overvoltage flag indicator
(FLAGV) low to notify the processor.

The MAX4880 internal current-limited switch limits the
charge current flowing to the battery to 525mA. The
switch opens when the battery voltage reaches its full­charged state (4.2V), and a flag (BAT_OK) asserts to
notify the processor. The MAX4880 includes a switch­control input (CB) to turn off the internal current-limited
switch, regardless of the battery voltage.

The MAX4880 also features a built-in startup delay that
allows the adapter voltage to settle down before turning
on the MOSFET. Other features include 15kV ESD pro­tection for the input and a shutdown function (EN) to
turn off the external n-channel MOSFET.

The MAX4880 is available in a space-saving 10-pin
TDFN package and is specified for operation over the
extended -40°C to +85°C temperature range.

Applications

Cell Phones

Digital Still Cameras

PDAs and Palmtop Devices

MP3 Players

Features

♦ Overvoltage Protection Up to 28V

♦ Preset 5.6V Overvoltage Trip Level

♦ Internal 525mA Current-Limited Switch

♦ ±1.2% Accurate Battery Disconnect (4.2V)

♦ Drives Low-Cost n-Channel MOSFET

♦ Internal 50ms Startup Delay
♦ Overvoltage/Undervoltage-Fault FLAGV Indicator
♦ Battery-Voltage-Trip BAT_OK Indicator

♦ Undervoltage Lockout

♦ Thermal Shutdown Protection

♦ Tiny 10-Pin TDFN Package

MAX4880

Overvoltage-Protection Controller with

Internal Disconnect Switch

________________________________________________________________ Maxim Integrated Products 1

FLAGV

GND

BTB

BTB_SNS

MAX4880

BAT_OK

IN

GATE

BTA

EN

3mm x 3mm TDFN

TOP VIEW

CB

134

10 8 7

2

9

5

6

Pin Configuration

Ordering Information

AC-DC

ADAPTER

5.25V

GATEIN

FLAGV
BAT_OK

BTB_SNS

Li+

BTB

BTA

CB
EN

GND

DC-DC

CONVERTER

V

IO

MAX4880

Typical Operating Circuit

19-3776; Rev 0; 7/05

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.

PART

TEMP RANGE

PIN­PACKAGE

TOP

MARK

MAX4880ETB

APJ

* EP = Exposed Pad

-40°C to +85°C 10 TDFN-EP*

MAX4880

Overvoltage-Protection Controller with
Internal Disconnect Switch

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)

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.

(All voltages referenced to GND.)

IN ............................................................................-0.3V to +30V

GATE ......................................................................-0.3V to +12V

EN, CB, FLAGV, BAT_OK, BTA, BTB, BTB_SNS .....-0.3V to +6V

Continuous Power Dissipation (T

A

= +70°C)

10-Pin TDFN (derate 18.5mW/°C above +70°C) ...1481.5mW

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

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

INPUT VOLTAGE (IN)

Input Voltage Range V

IN

1.2

V

Overvoltage Trip Level OVLO VIN rising 5.5 5.6 5.7 V

O ver vol tag e- Tr i p - Level H yster esi s

50 mV

Undervoltage-Lockout Threshold

UVLO VIN falling 4.2

4.5 V

Undervoltage-Lockout Hysteresis

50 mV

Supply Current

No load, VIN = 5.4V, VEN = 0 or 5.5V,
V

CB

= 0 or V

IN

380 µA

INTERNAL SWITCH

BTA Input Range V

BTA

2.8 5.7 V

BTA Undervoltage Lockout

Falling edge 2.4 2.7 V

BTA-Undervoltage-Lockout
Hysteresis

50 mV

BTB-Switch-Disconnect Trip
Level

V

BTB-Switch-Disconnect
Hysteresis

mV

Switch-Forward Current Limit I

FWD

600 mA

TA = +25°C 600

Switch-Reverse Current Limit I

REV

650

mA

Voltage Drop (V

BTA

– V

BTB

)I

L

= 400mA 110 mV

BTB Off Current

V EN = 0 ( V

C B

= 0, or V

IN

< V

U V L O

and V

BTA

= 0)

1µA

GATE

GATE Voltage V

GATEIGATE

sourcing 1µA , VIN = 5V 9 10 V

GATE Pulldown Current I

PD

VIN > V

OVLO

, V

GATE

= 5V 60 mA

TIMING

GATE Startup Delay t

START

VIN > V

UVLO

, V

GATE

> 0.3V (Figure 1) 20 50 80 ms

FLAGV Delay Time t

DELAYVGATE

= 0.3V,V

FLAGV

= 2.4V (Figure 1) 20 50 80 ms

GATE Turn-On Time t

GON

7ms

GATE Turn-Off Time t

GOFF

VIN increasing from 5V to 8V at 3V/µs,
V

GATE

= 0.3V, C

GATE

= 1500pF (Figure 2)

620µs

I

+ I

IN

BTA

UVLO

BTB

TRIP

I

BTB-OFF

BTA

V

= 0.3V to 8V , C

GAT E

4.35

240

4.10 4.20

200

450 525

= 1500p F ( Fi g ur e 1)

GAT E

28.0

MAX4880

Overvoltage-Protection Controller with

Internal Disconnect Switch

_______________________________________________________________________________________ 3

Note 1: All devices are 100% tested at TA= +25°C. Electrical limits over the full temperature range are guaranteed by design.

ELECTRICAL CHARACTERISTICS (continued)

(VIN= 5V, 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

FLAGV Assertion Delay t

FLAGV

VIN increasing from 5V to 8V at 3V/µs,
V

FLAGV

= 0.4V (Figure 2)

5.8 µs

Initial Overvoltage Fault Delay t

OVP

VIN increasing from 0 to 8V,
I

GATE

= 80% of IPD (Figure 3)

ns

Disable Time t

DIS

VEN = 2.4V, V

GATE

= 0.3V (Figure 4)

ns

EN, CB INPUTS

Input-High Voltage V

IH

1.4 V

Input-Low Voltage V

IL

0.5 V

Input Leakage 1µA

FLAGV, BAT_OK OUTPUTS

Output Voltage Low V

OL

I

SINK

= 1mA, FLAGV, BAT_OK assert 0.4 V

Leakage Current V

BAT_OK

= V

FLAGV

= 5.5V 1 µA

THERMAL PROTECTION

Thermal Shutdown

°C

Thermal Hysteresis 40 °C

Typical Operating Characteristics

(VIN= 5V, TA= +25°C, otherwise noted.)

IIN + I

BTA

CURRENT vs. INPUT VOLTAGE

INPUT VOLTAGE (V)

I

IN

+ I

BTA

CURRENT (μA)

MAX4880 toc01

0 5 10 15 20 25 30

0

50

100

150

200

250

300

350

400

VEN = 0
V

CB

= 5V

OVLO TRIP POINT

UVLO TRIP POINT

IIN + I

BTA

CURRENT vs. TEMPERATURE

TEMPERATURE (°C)

I

IN

+ I

BTA

CURRENT (μA)

MAX4880 toc02

-40 -15 10 35 60 85

0

50

100

150

200

250

300

350

400

GATE VOLTAGE vs. INPUT VOLTAGE

INPUT VOLTAGE (V)

GATE VOLTAGE (V)

MAX4880 toc03

012345678

0

3

6

9

12

UVLO TRIP POINT

OVLO TRIP POINT

100

580

+150