Datasheet MAX1614EUA, MAX1614C-D Datasheet (Maxim)

19-1176; Rev 0; 12/96

High-Side, N-Channel MOSFET

Switch Driver

_______________General Description

The MAX1614 drives high-side, N-channel power MOSFETs
to provide battery power-switching functions in portable
equipment. N-channel power MOSFETs typically have
one-third the on-resistance of P-channel MOSFETs of simi­lar size and cost. An internal micropower regulator and
charge pump generate the high-side drive output voltage,
while requiring no external components.

The MAX1614 also features a 1.5%-accurate low-battery
comparator that can be used to indicate a low-battery
condition, provide an early power-fail warning to the sys­tem microprocessor, or disconnect the battery from the
load, preventing deep discharge and battery damage. An
internal latch allows for pushbutton on/off control with very
low current consumption. Off-mode current consumption
is only 6µA while normal operation requires less than
25µA. The MAX1614 is available in the space-saving
µMAX package that occupies about 60% less space than
a standard 8-pin SO.

________________________Applications

Notebook Computers
Portable Equipment
Hand-Held Instruments
Battery Packs

____________________________Features

♦ Internal On/Off Latch
♦ High-Side, N-Channel Power MOSFET Drive
♦ 25µA (max) Quiescent Current
♦ 6µA (max) Off Current
♦ Requires No External Components
♦ 1.5%-Accurate Low-Battery Detector
♦ Space-Saving µMAX Package
♦ 5V to 26V Input Voltage Range
♦ Drives Single or Back-to-Back MOSFETs
♦ Controlled Turn-On for Low Inrush Current

______________Ordering Information

PART

MAX1614C/D
MAX1614EUA -40°C to +85°C

*

Contact factory for dice specifications.

TEMP. RANGE PIN-PACKAGE

0°C to +70°C

Dice*
8 µMAX

MAX1614

__________Typical Operating Circuit

NN

LOAD

__________________Pin Configuration

OPTIONAL FOR 
REVERSE CURRENT 
PROTECTION

SRCGATE

ON

MAX1614

BATT

R1

LBI

R2

GND

________________________________________________________________

OFF

LBO

TOP VIEW

ON
OFF
LBO

LBI

1
2
3
4

8

BATT
SRC

MAX1614

µMAX

Maxim Integrated Products

7

GATE

6
5

GND

1

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

High-Side, N-Channel MOSFET

OFF

Switch Driver

ABSOLUTE MAXIMUM RATINGS

BATT, SRC to GND.................................................-0.3V to +30V

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

GATE to GND.........................................................-0.3V to +36V

GATE + SRC Sink Current, Continuous.............................2.7mA

LBI, LBO, ON, OFF to GND....................................-0.3V to +12V

LBO Current..........................................................................5mA

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

MAX1614

absolute maximum rating conditions for extended periods may affect device reliability.

Continuous Power Dissipation (T

µMAX (derate 4.10mV/°C above +70°C) .....................330mW

Operating Temperature Range ...........................-40°C to +85°C

Junction Temperature......................................................+150°C

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

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

ELECTRICAL CHARACTERISTICS

(V

= 15V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

BATT

CONDITIONS

V

- V

> 3V, SRC = BATT

SRC

= 26V, ON = OFF = unconnected,

= 1.5V

LBI

= 15V, ON = OFF = unconnected,

= 1.5V,

LBI

= 26V, ON = OFF = unconnected,

= 0A, device latched on, V

LBI

BATT

= 1.5V,

= 15V,

= 0A

= V

= V

SRC

BATT

= 15V

SRC

= 4V, device latched off

LBI

= V

BATT

/ 4

= 5V
= 26V
= 5V

= 5V,

BATT Shutdown Current

Quiescent Current

INTERNAL CHARGE PUMP

GATE Drive Voltage

LOW-BATTERY COMPARATOR

LBI Trip Level
LBI Trip Hysteresis
Minimum V

for Valid LBO

BATT

LBI Input Current

LBO Low Voltage
LBO High Leakage

CONTROL INPUTS (ON,

Input Low Voltage
Input High Voltage
Minimum Input Pulse Width

GATE

V

SHDN

I

BATT

I

SRC

BATT

I

GATE

V

BATT

I

GATE

SRC = BATT

+

V
I

GATE

= 0A, device latched off, V

= 0A, device latched on, V

BATT

SRC = BATT

Measured from GATE to SRC, V
I

V

GS

TH

GATE

Measured from GATE to SRC, V
I

= 1.5µA

GATE

V

GATE

V

GATE

LBI input falling

Tested at V
V

= 1.3V

LBI

OL
OH

LBI

I

SINK

V

LBO

= 1mA
= 11.5V

)

Tested at 2V
Tested at 0.6V
V
V
V

BATT
BATT
BATT

IL
IH

PW

= +70°C)

A

17 30

21 40

6.5 8 9.0

3

TH

UNITSMIN TYP MAXSYMBOLPARAMETER

V526BATT Operating Range

µA47I

µA
µA

V

µA15 60GATE Drive Output Current

mA0.5 2GATE Discharge Current

V1.182 1.20 1.218V
V0.02V
V0.9 4

nA10I

V0.4V

µA0.5V

µA0.5Minimum Input Pull-Up Current
µA1.5 2Maximum Input Pull-Up Current

V0.6V
V2.0V

µs0.5 1.0t

2 _______________________________________________________________________________________

High-Side, N-Channel MOSFET

Switch Driver

ELECTRICAL CHARACTERISTICS

(V

= 15V, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)

BATT

PARAMETER SYMBOL MIN TYP MAX UNITS

BATT Operating Range 5.0 26 V
BATT Shutdown Current

Quiescent Current

INTERNAL CHARGE PUMP

INTERNAL CHARGE PUMP

I

SHDN

I

BATT

I

SAC

V

- V

GATE

V

= 26V, ON = OFF = unconnected,

BATT

= 0A, device latched off, V

I

GATE

+

V

= 26V, ON = OFF = unconnected,

BATT

= 0A, device latched on, V

I

GATE

Measured from GATE to SRC, V
I

= 0A

GATE Drive Voltage V

GS

GATE Drive Output Current 15 60 µA

LOW BATTERY COMPARATOR

LOW-BATTERY COMPARATOR

LBI Trip Level V

TH

GATE

Measured from GATE to SRC, V
I

= 1.5µA, V

GATE

V

= V

GATE

LBI input falling

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

CONDITIONS

> 3V, SRC = BATT

SRC

= 5.25V

SRC

= 15V

SRC

LBI

LBI

BATT

BATT

= 1.5V

= 1.5V

= 15V,

= 5.25V,

8 µA

40

6.5 9.0

3

1.176 1.20 1.224 V

MAX1614

µA

V

__________________________________________Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

ON SUPPLY CURRENT

vs. V

V

BATT

BATT

TA = +85°C

20

(V)

= +25°C

T

A

T

= -40°C

A

25

MAX1614-01

4.0

3.5

3.0

2.5

2.0

SHUTDOWN CURRENT (µA)

1.5

1.0
530

10 15

22
20

18
16

14
12

SUPPLY CURRENT (µA)

10

8
6

530

10 15

_______________________________________________________________________________________ 3

OFF SUPPLY CURRENT

vs. V

BATT

TA = +85°C
TA = +25°C

= -40°C

T

A

20

V

(V)

BATT

1.30

MAX1614-02

1.28

1.26

1.24

1.22

LBI THRESHOLD (V)

1.20

1.18

25

1.16

LOW-BATTERY THRESHOLD

vs. TEMPERATURE

V

= 15V

BATT

V

RISING

LBI

V

FALLING

LBI

-40 100

-20 0

20 60

40

TEMPERATURE (°C)

80

MAX1614-05

High-Side, N-Channel MOSFET
Switch Driver

____________________________Typical Operating Characteristics (continued)

(TA = +25°C, unless otherwise noted.)

GATE-DISCHARGE CURRENT

vs. GATE VOLTAGE

2.5

2.0

MAX1614

1.5

1.0

0.5

GATE-DISCHARGE CURRENT (mA)

0

-0.5
020

48

GATE AND SOURCE TRANSITIONS

FOR TYPICAL MOSFET LOAD

5V/div



34

T

= -40°C

A

= +25°C

T

A

TA = +85°C

12

16214610 18

V

(V)

GATE

MAX1614-04

33

32
31

30
29

28

GATE-CHARGING CURRENT (µA)

27
26

GATE-CHARGING CURRENT

vs. TEMPERATURE

V

= 15V

BATT

-40 0 80 100

40-20 6020

TEMPERATURE (°C)

MAX1614--03

GATE-CHARGING CURRENT

vs. BATT VOLTAGE

30
29
28
27
26
25
24

GATE-CHARGING CURRENT (µA)

23
22

530

10 15

V

BATT

(V)

T

A =

T

-40°C

A =

20

25

+85°C

MAX1614-06

GATE TURN-ON TRANSITION

FOR TYPICAL MOSFET LOAD

V

V

GATE

SRC

Si9936 MOSFETS

MAX1614-07

I

= 1A

LOAD

ON = GND

5V/div

0V

V

V

GATE

SRC

Si9936 MOSFETS

MAX1614-08

I

= 1A

LOAD

C

= 400pF

iss

ON = GND

V

V

OFF

1ms/div

OFF

0V

100µs/div

GATE TURN-OFF TRANSITION

FOR TYPICAL MOSFET LOAD

Si9936 MOSFETS

V

GATE

V

SRC

MAX1614-09

I

LOAD

C

iss

ON = GND

= 1A

= 400pF

5V/div

V

OFF

20µs/div

4 _______________________________________________________________________________________

High-Side, N-Channel MOSFET

Switch Driver

______________________________________________________________Pin Description

PIN

1

2

3

ON

OFF

LBI4

GATE6

SRC7

SET Input to the On/Off Latch. Pulse ON low with OFF high to turn on the external MOSFET switch. When
both ON and OFF are low, the part is off.

RESET Input to the On/Off Latch. Pulse OFF low with ON high to turn off the external MOSFET switch. When
both ON and OFF are low, the part is off.

Open-Drain, Low-Battery Comparator Output. LBO is low when V
Low-Battery Comparator Input. LBO goes low when V

between BATT, LBI, and GND to set the battery undervoltage trip threshold (see
System GroundGND5
Gate-Drive Output. Connect to the gates of external, N-channel MOSFETs. When the MAX1614 is off, GATE

actively pulls to GND.
Source Input. Connect to the sources of external, N-channel MOSFETs. When the MAX1614 is off, SRC

actively pulls to GND.
Battery Input. Connect to a battery voltage between 5V and 26V.BATT8

_______________Detailed Description

The MAX1614 uses an internal, monolithic charge pump
and low-dropout linear regulator to supply the required
8V VGSvoltage to fully enhance an N-channel MOSFET
high-side switch (Figure 1). The charge pump typically
supplies 30µA, charging 800pF of gate capacitance in
400µs (V
add a small capacitor between the GATE and SRC
pins. When turned off, GATE and SRC pull low and typi­cally discharge an 800pF gate capacitance in 80µs.

The MAX1614 provides separate on/off control inputs
(ON and OFF). ON and OFF connect, respectively, to
the SET and RESET inputs of an internal flip-flop. When
ON is pulsed low (with OFF = high), the internal charge
pump turns on, and GATE is pumped to 8V above SRC,
turning on the external MOSFETs. The charge pump
maintains gate drive to the external MOSFETs until OFF
is pulsed low. When this happens, the internal charge
pump turns off, and GATE discharges to ground
through an internal switch. For slower turn-on times,
simply add a small capacitor.

= 15V). For slower turn-on times, simply

BATT

__________ Applications Information

Connecting ON/

ON and OFF internally connect to 2µA max pull-up
current sources (Figure 1). The open-circuit voltage
for ON and OFF ranges from 7V to 10.5V (nominally

8.5V). Since the current sources are relatively weak,
connecting ON and OFF directly to logic powered from

OFF

to 3V or 5V Logic

FUNCTIONNAME

is below the trip point.LBO

LBI

falls below 1.20V (typ). Connect a voltage divider

LBI

lower voltages (e.g., 3V or 5V) poses no problem if the
gate outputs driving these pins can sink at least 2µA
while high.

Although the MAX1614 shutdown function was designed
to operate with a single pushbutton on/off switch, it can
also be driven by a single gate. Connect ON to GND
and drive OFF directly (Figure 2).

Typical Operating Circuit

).

Maximum Switching Rate

The MAX1614 is not intended for fast switching appli­cations. In fact, it is specifically designed to limit the
rate of change of the load current, ∆I/∆t. The maximum
switching rate is limited by the turn-on time, which is a
function of the charge-pump output current and the
total capacitance on GATE (C
on time as a function of external MOSFET gate capaci­tance using the Gate Charging Current vs. V
in the

Typical Operating Characteristics

time is small compared to turn-on time, the maximum
switching rate is approximately 1/tON.

). Calculate the turn-

GATE

. Since turn-off

BATT

graph

Adding Gate Capacitance

The charge pump uses an internal monolithic transfer
capacitor to charge the external MOSFET gates.
Normally, the external MOSFET’s gate capacitance is
sufficient to serve as a reservoir capacitor. If the
MOSFETs are located at a significant distance from the
MAX1614, place a local bypass capacitor (100pF typ)
across the GATE and SRC pins. For slower turn-on
times, simply add a small capacitor between GATE and
SRC.

MAX1614

_______________________________________________________________________________________ 5

High-Side, N-Channel MOSFET
Switch Driver

BATT

MAX1614

1.21V

LBI

LBO

P

8.5V
LDO

N

POWER-ON
RESET (BATT < 2V)

SOFT

START

1µA1µA

C

PUMP

P

N

50kHz

OSC

ON

GATE

SRC

OFF

ON

ON

OFF

STATE

0

0

OFF

0

1

1

0

1

1

GND

ON

OFF

LAST VALID

STATE

MAX1614

N

Figure 1. Functional Diagram

6 _______________________________________________________________________________________

High-Side, N-Channel MOSFET

Switch Driver

SHUTDOWN

(CMOS OR TTL LOGIC)

Figure 2. Single-Line Shutdown Control

NN

MAX1614

OFF

GND

SRCGATE

ON

ON

LOAD

Simple Low-Battery Disconnect/Fresh

Battery Reconnect Circuit

A simple undervoltage disconnect circuit is often desir­able to prevent damage to secondary batteries due to
repeated deep discharge or cell reversal. The

Operating Circuit

turns off the MAX1614, disconnecting

Typical

the battery from the load when the battery voltage
falls below the minimum battery voltage required,
(V

LOW BATT

). V

LOW BATT

= (R1 + R2) / R2 x VTHwhere
VTHis the LBI input threshold (1.20V typ). When fresh
cells are installed or the batteries are recharged, a µC
or pushbutton reconnects the load.

Using

LBO

to Generate Early

Power-Fail Interrupt

Many applications require an early warning indicating
that power is failing so that the microprocessor (µP)
can take care of any “housekeeping” functions (storing
current settings in memory, etc.) before the power fails.
Connect LBI through a resistor divider across the bat­tery, and connect LBO to the µP nonmaskable interrupt
(NMI). Set the threshold so that LBO goes low when the
battery decays to a point where regulation begins to
degrade (Figure 4). V

LOW BATT

where VTHis the LBI input threshold (1.20V typ). Once
housekeeping is complete, the µP can turn off the load
by pulling OFF low.

= (R1 + R2) / R2 x V

TH,

MAX1614

MAX1614

BATT

R1

LBI

R2

GND

Figure 3. Single-Pushbutton On/Off Control

OFF

LBO

TO µC

On/Off Control with a

Single Pushbutton Switch

The MAX1614’s separate on and off inputs allow maxi­mum flexibility in controlling the external MOSFETs.
Connect a pushbutton switch to the ON pin and micro­controller (µC) I/O for single-button control. Connect the
OFF pin to another µC I/O pin. On the first button
depression, the MAX1614 turns on automatically; the
signal is also detected by the µC. When the button is
depressed a second time, the µC wraps around and
turns off the MAX1614 by pulling low on the OFF pin
(Figure 3).

_______________________________________________________________________________________ 7

NN

SRCGATE

ON

MAX1614

BATT

R1

LBI

R2

GND

Figure 4. Using LBO to Generate Early Power-Fail Interrupt

OFF

LBO

LOAD

TO µC
PORT PINS

TO µC 
NONMASKABLE
INTERRUPT

High-Side, N-Channel MOSFET
Switch Driver

Increasing Low-Battery

Comparator Hysteresis

The MAX1614 contains an on-chip comparator with 2%
hysteresis for low-battery detection. If more than 2%
hysteresis is needed on the low-battery comparator and
LBO is connected to OFF, use the circuit in Figure 5 to
add hysteresis. The circuit of Figure 5 shows LBO con-
trolling an N-channel MOSFET that shorts R2 to add
positive feedback to the trip point. This is necessary to

MAX1614

prevent loading down the 1µA pull-up at OFF (Figure 1).

2N7002

(SOT23)

___________________Chip Information

TRANSISTOR COUNT: 264
SUBSTRATE CONNECTED TO GND

R1 = 909kΩ
R2, R3 = 150kΩ

= 8.5V

V

L

= 9.8V

V

H

HYSTERESIS = 6%

Figure 5. Increasing Hysteresis of the Battery Disconnect
Circuit

BATT

R1

R2N

LBI

R3

FALLING TRIP POINT V


= VTH

V

L

N

SRCGATE

MAX1614

GND

R1 + R3

( )

R3

OFF

LBO



L

ON

RISING TRIP POINT VH


= VTH

V

H

LOAD

R1 + R2 + R3

( )

R3

________________________________________________________________Package Information

DIM

C

A

0.101mm

e

A1B

E H

0.004 in

L

α

A1

C
D

H

8-PIN µMAX

MICROMAX SMALL-OUTLINE

PACKAGE

D

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

8

___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

8

___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

8

___________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

INCHES MILLIMETERS



A

0.036

0.004

B

0.010

0.005

0.116

E

0.116

e

0.188

L

0.016

α

MIN

0°

MAX

0.044

0.008

0.014

0.007

0.120

0.120





0.198

0.026
6°

MIN

0.91

0.10

0.25

0.13

2.95

2.95

4.78

0.41
0°

MAX

1.11

0.20

0.36

0.18

3.05

3.05

0.650.0256





5.03

0.66
6°

21-0036D