Maxim MAX1612EEE Datasheet

General Description

The MAX1612/MAX1613 manage the bridge battery
(sometimes called a hot-swap or auxiliary battery) in
portable systems such as notebook computers. They
feature a step-up DC-DC converter that boosts 2-cell or
3-cell bridge-battery voltages up to the same level as
the main battery. This voltage boosting technique
reduces the number of cells otherwise required for a 6­cell plus diode-OR bridging scheme, reducing overall
size and cost. Another key feature is a trickle-charge
timer that minimizes battery damage caused by con­stant charging and eliminates trickle-charge current
drain on the main battery once the bridge battery is
topped off.

These devices contain a highly flexible collection of
independent circuit blocks that can be wired together
in an autonomous stand-alone configuration or used in
conjunction with a microcontroller. In addition to the
boost converter and charge timer, there is a micropow­er linear regulator (useful for RTC/CMOS backup as
well as for powering a microcontroller) and a high-pre­cision low-battery detection comparator.

The two devices differ only in the preset linear-regulator
output voltage: +5.0V for the MAX1612 and +3.3V for
the MAX1613. Both devices come in a space-saving
16-pin QSOP package.

Applications

Notebook Computers
Portable Equipment
Backup Battery Applications

Features

♦ Reduce Battery Size and Cost
♦ Four Key Circuit Blocks

Adjustable Boost DC-DC Converter
NiCd/NiMH Trickle Charger
Always-On Linear Regulator (+28V Input)
Low-Battery Detector

♦ Low 18µA Quiescent Current
♦ Selectable Charging/Discharging Rates
♦ Preset Linear-Regulator Voltage

5V (MAX1612)

3.3V (MAX1613)

♦ 4V to 28V Main Input Voltage Range
♦ Internal Switch Boost Converter
♦ Small 16-Pin QSOP Package

MAX1612/MAX1613

Bridge-Battery Backup Controllers

for Notebooks

________________________________________________________________

Maxim Integrated Products

1

16
15
14
13
12
11
10

9

1
2
3
4
5
6
7
8

ISET LRI

LRO
PGND
CD
CC
GND
LBI
FB

TOP VIEW

MAX1612
MAX1613

QSOP

BBATT

LX

DCMD

LBO

BBON

CCMD

FULL

Typical Operating Circuit

19-4785; Rev 0; 11/98

PART

MAX1612EEE
MAX1613EEE

-40°C to +85°C

-40°C to +85°C

TEMP. RANGE PIN-PACKAGE

16 QSOP
16 QSOP

EVALUATION KIT MANUAL

FOLLOWS DATA SHEET

Pin Configuration

Ordering Information

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone].

MAIN BATTERY

OR

WALL

ADAPTER

AUXILIARY

BRIDGE

BATTERY

LRI

BBATT

MAX1613

APPLICATION

CIRCUIT

DC-DC
OUTPUT

V+

MAX1630MAX1612

DC-DC

CONVERTER

+3.3V

+5V

V

CPU

MAX1612/MAX1613

Bridge-Battery Backup Controllers
for Notebooks

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V

LRI

= V

ISET

= 20V, CCMD = DCMD = BBON = LRO, V

BBATT

= 3V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +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.

LRI, ISET to GND....................................................-0.3V to +30V

LX to GND ..............................................................-0.3V to +14V

PGND to GND .......................................................-0.3V to +0.3V

BBATT, LRO, CCMD, DCMD, FULL, BBON,

LBO to GND ..........................................................-0.3V to +6V

CC, CD, LBI, FB to GND...........................-0.3V to (V

LRO

+ 0.3V)

FB, LBI, ISET, and BBATT Current......................................50mA

LRO Output Current ...........................................................50mA

Continuous Power Dissipation (T

A

= +70°C)

QSOP (derate 8.30mW/°C above +70°C).................... 667mW

Operating Temperature Range

MAX1612/MAX1613EEE...................................-40°C to +85°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec)............................ +300°C

I

SINK

= 1mA

V

LBO

= V

FULL

= 5.5V

V

BBON

≥ 2V

V

LBI

= 1.9V

MAX1613

MAX1612

V

ISET

= 28V, V

BBATT

= 0

LRO rising hysteresis = 200mV

CCMD = GND, I

ISET

= 10mA, V

BBATT

= 2V,

%loss = [(I

ISET

- I

BBATT

) / I

ISET

) · 100%

V

DCMD

= 0, R

BBON

= 1MΩ to GND

(boost converter on)

5.7V ≤ V

LRI

≤ 28V

(MAX1612)

I

ISET

= 10mA, V

CCMD

= 0, V

BBATT

= 2V

V

ISET

= 0 or 28V, V

BBATT

= 6V

CONDITIONS

LBO, FULL Output Voltage Low

V0.4

LBO, FULL Output Leakage
Current

µA1I

LBO, IFULL

nA

0.2 10

I

LBI

LBI Input Current

V

1.955 2 2.045

V

LBTH

LBI Rising Trip Voltage

V

1.76 1.8 1.84

V

LBTL

LBI Falling Trip Voltage

%

0.1 5

Charge-Switch Loss Current

V

0.5 1 1.3

Charge-Switch On Voltage

µA

-5 5

I

BBATT(LEAK

)BBATT Leakage Current

18 28

I

LRI

4V ≤ V

LRI

≤ 28V

(MAX1613)

0 ≤ I

LRO

≤ 10mA

4 28

V

5.7 28

V

LRI

Linear-Regulator Input Voltage
Range

µA

0.3 5

I

ISET(LEAK

)ISET Leakage Current

V

2.65 2.97

V

UVLO

Linear-Regulator Output
Undervoltage Lockout
Threshold

V

3.1 3.3 3.5

µA

42 58

Linear-Regulator Quiescent
Current

4.7 5.0 5.3

V

LRO

Linear-Regulator Output Voltage

UNITMIN TYP MAXSYMBOLPARAMETER

Overdrive = 100mV µs

20

t

PD

LBI Comparator Response Time

BATTERY CHARGER

LOW-BATTERY COMPARATOR

MAX1612/MAX1613

Bridge-Battery Backup Controllers

for Notebooks

_______________________________________________________________________________________

3

Typical Operating Characteristics

(Circuit of Figure 3, TA = +25°C, unless otherwise noted.)

CONDITIONS UNITMIN TYP MAXSYMBOLPARAMETER

CCMD, DCMD

V

CCMD

= 0, CC = GND

V

DCMD

= 0, CD = GND

Resets the counter

Voltage that allows a new cycle, defined as
(V

BBATT

- VLX) (see

DC-DC Converter

section)

VFB= 2.1V
R

BBON

= 100kΩ to GND

VLX= 12V

CCC= 33nF

ILX= 200mA

CCD= 3.3nF

V

0.8

V

IL

Logic Input Low Level

%

-1 1

CD to CC Current Matching

V

0.4

ISET Logic Input Low Voltage

Hz

60 75.8 95

CC

OSC

CC Oscillator Frequency

Hz

600 758 950

CD

OSC

CD Oscillator Frequency

V

1.95 2.05

V

FB

FB Trip Point

µA

4.35 5.00 5.65

CC Output Current

V2.1

BBON Logic Input Low Voltage

V

-0.2 -0.1 0.2

LX Zero Crossing Trip Threshold

nA

0.15 10

I

FB

FB Input Current

A

0.580 0.835 1.100

I

PEAK

LX Switch Current Limit

µA

0.01 10

LX Off-Leakage

Ω

0.5 1.5

R

DSON

LX On-Resistance

ELECTRICAL CHARACTERISTICS (continued)

(V

LRI

= V

ISET

= 20V, CCMD = DCMD = BBON = LRO, V

BBATT

= 3V, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.) (Note 1)

CCMD, DCMD

V

2.2

V

IH

Logic Input High Level

V

CCMD

, V

DCMD

= 0 to V

LRO

µA

1

I

(CCMD),

I

(DCMD)

Logic Input Leakage Current

TIMER BLOCK

DC-DC CONVERTER

Note 1: Specifications from 0°C to -40°C are guaranteed by design, not production tested.

0

20

40

60

80

100

120

0 105 15 20 25 30 35 40 45

DISCHARGE TIME

vs. OUTPUT CURRENT

MAX612-01

OUTPUT CURRENT (mA)

DISCHARGE TIME (MINUTES)

2 CELLS (SANYO N-50AAA)

V

OUT

= 7V

V

OUT

= 5V

100k

1

0.1 10 1001 1000

OSCILLATOR FREQUENCY

vs. CAPACITANCE

10

MAX1612-02

CAPACITANCE (nF)

OSCILLATOR FREQUENCY (Hz)

100

1k

10k

CD

CC

90
80

70

0

1µ 10µ 1m 10m

100m

100µ 1

EFFICIENCY vs. OUTPUT CURRENT

(BBATT = 3.6V)

MAX612-03

OUTPUT CURRENT (A)

EFFICIENCY (%)

30
20
10

60
50

40

V

OUT

= 7V

V

OUT

= 6V

V

OUT

= 5V

BBATT = 3.6V
R

BBON

= 240kΩ
NOTE: DC-DC
CONVERTER
SUPPLIES V

LRI

MAX1612/MAX1613

Bridge-Battery Backup Controllers
for Notebooks

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(Circuit of Figure 3, TA = +25°C, unless otherwise noted.)

90
80

70

0

1µ 10µ 1m 10m

100m

100µ 1

EFFICIENCY vs. OUTPUT CURRENT

(BBATT = 2.4V)

MAX612-04

OUTPUT CURRENT (A)

EFFICIENCY (%)

30
20
10

60
50

40

V

OUT

= 7V

V

OUT

= 6V

V

OUT

= 5V

BBATT = 2.4V
R

BBON

= 240kΩ
NOTE: DC-DC
CONVERTER
SUPPLIES V

LRI

90
80

70

0

1µ 10µ 1m 10m

100m

100µ 1

EFFICIENCY vs. OUTPUT CURRENT

(BBATT = 6V)

MAX612-05

OUTPUT CURRENT (A)

EFFICIENCY (%)

30
20
10

60
50

40

BBATT = 3.6V

BBATT = 2.4V

V

OUT

= 6V

R

BBON

= 240kΩ
NOTE: DC-DC
CONVERTER
SUPPLIES V

LRI

0

20

10

40

30

50

0 10 155 20 25 30

QUIESCENT CURRENT

vs. LRI VOLTAGE

MAX612-06

V

LRI

(V)

QUIESCENT CURRENT (µA)

MAX1612

MAX1612

MAX1613

MAX1613

R

BBON

= 100kΩ TO GND

V

BBON

= V

LRO

0

600

400

200

800

1000

1200

5 13117 9 15 17 19 21 23 25

PEAK CURRENT vs. BBON CURRENT

MAX612-07

BBON CURRENT (µA)

PEAK CURRENT (mA)

3.20

3.24

3.22

3.26

3.32

3.30

3.34

3.28

3.36

0 4 6 8 102 12 14 16 18 20

MAX1613

LRO VOLTAGE vs. LOAD CURRENT

MAX612-10

LOAD CURRENT (mA)

V

LRO

(V)

V

LRI

= 20V

-2.0

-1.0

-1.5

0

-0.5

0.5

1.0

1.5

2.0

2.0 3.0 3.52.5 4.0 4.5 5.0 5.5 6.0

BBATT LEAKAGE CURRENT
vs. BBATT INPUT VOLTAGE

MAX612-08

BBATT INPUT VOLTAGE (V)

BBATT LEAKAGE CURRENT (µA)

3.25

3.27

3.31

3.29

3.33

3.35

0 105 15 20 25 30

MAX1613

LRO VOLTAGE vs. LRI VOLTAGE

MAX612-09

V

LRI

(V)

V

LRO

(V)

I

LOAD

= 5mA

100

150

250

200

300

350

120 200160 240 280 320 360

SWITCHING FREQUENCY vs. R

BBON

MAX612-11

R

BBON

(kΩ)

SWITCHING FREQUENCY (kHz)