MAXIM MAX4836, MAX4837 User Manual

General Description

The MAX4836/MAX4837 family of low-dropout (LDO)
linear regulators feature an accurate current-limiting
switch with an integrated FLAG or RESET function. These
devices operate from 2.5V to 5.5V and deliver up to
500mA of load current at a preset output voltage. Preset
output voltage levels are 1.8V/2.5V/2.8V/3.0V/3.3V.

The MAX4836/MAX4837 offer a programmable soft­start control function to eliminate false reset during
startup. The MAX4836 provides a FLAG function to noti­fy the system when the load current exceeds the limit.
The MAX4837 provides a RESET function to notify the
system when the output drops below the threshold.
Additionally, reverse-current protection prevents cur­rent flowing from the output to the input. Other features
include a low 90µA quiescent current, a 0.1µA shut­down current.

The MAX4836/MAX4837 are available in space-saving
6-pin SOT23 and TDFN packages. Each device is speci­fied over the -40°C to +85°C extended temperature
range. Contact factory for other programmed output volt­age versions from 1.5V to 3.3V in 100mV increments.

For pin-compatible 100mA versions of this device, refer
to the MAX4832/MAX4833. For pin-compatible 250mA
versions of this device, refer to the MAX4834/MAX4835.

Applications

SDIO Ports and Devices Notebook Computers

USB Ports and Devices Cell Phones

PDAs and Palmtop Devices GPS Systems

Features

♦ Guaranteed Minimum 500mA Load Current

♦ Accurate Current Limit

♦ Preset Output Voltages: 1.8V/2.5V/2.8V/3.0V/3.3V

♦ 2.5V to 5.5V Supply Voltage Range

♦ Adjustable Soft-Start

♦ Low Dropout Voltage

♦ Thermal Shutdown

♦ Reverse-Current Protection

♦ Shutdown Output Discharge (MAX4837)

♦ Low 90µA Supply Current

♦ Ultra-Low 0.1µA Shutdown Current
♦ FLAG and Latch Off (MAX4836) or RESET

(MAX4837)

♦ Tiny SOT23 and TDFN (3mm x 3mm) Packages

MAX4836/MAX4837

500mA LDO Linear Regulators with

Current-Limiting Switch

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-3374; Rev 0; 7/04

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.

Note: “xy” are placeholders for the output voltage levels of the

devices. Insert the values found in Table 1 at the end of this doc­ument in the place of “xy”. The “_” is a placeholder for either the

RESET

or the

FLAG

feature. Insert “B” in the place of “_” for

RESET

and “C” for

FLAG

. “dd” is a placeholder for the reset
timeout period. Insert the values found in Table 2 in the place of
“dd.” For example, MAX4837EUT18BD2 has a 1.8V output volt­age,

RESET

feature, and a 30ms reset timeout period. Note that

“dd” applies only to the devices with

RESET

option and does not

apply to the devices with

FLAG

option. For devices with the

FLAG

option, leave dd blank. Standard versions require a mini­mum order increment of 2.5k units. Nonstandard versions must
be ordered in 10k unit increments. Contact factory for availability.
*Future product—contact factory for availability.

Pin Configurations

Pin Configurations continued at end of data sheet.

Tables 1 and 2 and Selector Guide appear at end of data
sheet.

TOP VIEW

1

IN

2

GND

SHDN

( ) MAX4836ETTxyC ONLY.

MAX4836/MAX4837

3

EXPOSED PADDLE

TDFN

OUT

6

5

SS

RESET

4

(FLAG)

PART TEMP RANGE PIN-PACKAGE

MAX4836EUTxy_-T* -40°C to +85°C 6 SOT23-6

MAX4836ETTxy_-T -40°C to +85°C 6 TDFN-6

MAX4837EUTxy_dd-T* -40°C to +85°C 6 SOT23-6

MAX4837ETTxy_dd-T -40°C to +85°C 6 TDFN-6

MAX4836/MAX4837

500mA LDO Linear Regulators with
Current-Limiting Switch

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= V

OUT

+ 1V, SHDN = IN, C

OUT

= 3.3µF, 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.

IN, SHDN, FLAG, OUT to GND ................................-0.3V to +6V

RESET to GND .........................................-0.3V to (V

OUT

+ 0.3V)

SS to GND ...................................................-0.3V to (V

IN

+ 0.3V)

IN to OUT ...............................................................................±6V

OUT Short Circuit to GND ..........................................Continuous

All Pins ESD Handling (Human Body Model).........................2kV

Continuous Power Dissipation (T

A

= +70°C)

6-Pin SOT23 (derate 9.1mW/°C above +70°C)................727mW

6-Pin TDFN (derate 24.4mW/°C above +70°C) ..........1951.2mW

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

Operating Junction Temperature Range...........-40°C to +125°C

Storage Temperature Range .............................-65°C to +150°C

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

Operating Voltage V

Input Undervoltage Lockout
Threshold

Input Undervoltage Lockout
Threshold Hysteresis

Quiescent Current I

Dropout Voltage (Note 2) I

Output Voltage Accuracy

Output Current I

Output Current Limit V

Reverse Current at V

Soft-Start Time (Note 3) t

Line Regulation (Note 4)

Load Regulation 100µA < I

Output Noise 10Hz to 100kHz, C

SHUTDOWN INPUT (SHDN)

OUT Discharge Resistance in
Shutdown (MAX4837)

SHDN Input-Voltage High V
SHDN Input-Voltage Low V
SHDN Input Hysteresis 30 mV
SHDN Input Leakage Current SHDN = IN or GND -100 +100 nA

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

IN

IN

V

UVLO

OUT

SS

VIN rising 2.00 2.25 V

Q

SHDN = IN, I
SHDN = IN, I

V

< VIN < V

UVLO

SHDN = GND, I

= 500mA

OUT

I

= 1mA to 500mA, TA = +25°C -1.3 +1.3

OUT

I

= 1mA to 500mA, TA = -40°C to +85°C -2 +2

OUT

= 0V 540 660 mA

OUT

V

= 5.5V, V

OUT

C

= not connected 0.5 1 2.0

SS

C

= 0.01µF 4 10 15

SS

C

= 0.1µF 40 100 150

SS

V

+ 0.5V < V

OUT

5.5V, I

LOAD

= 0 90 150

OUT

= 0,

OUT

(nominal)

OUT

= 0 0.1 2

OUT

TA = +25°C 200 300

T

= -40°C to +85°C 330

A

= 0V to V

IN

IN

= 100µA

< 500mA, VIN = V

LOAD

OUT

TA = +25°C -0.04 +0.02 +0.065

<

T

= -40°C to +85°C -0.05 +0.03 +0.08

A

+ 1V 1.3 %V

OUT

= 0.01µF 70 µV

SS

SHDN = GND 900 Ω

IH

IL

2.5 5.5 V

50 mV

150

500 mA

0.1 2 µA

1.4 V

0.5 V

%V

%V

µA

mV

NOM

ms

NOM

V

NOM

RMS

/

MAX4836/MAX4837

500mA LDO Linear Regulators with

Current-Limiting Switch

_______________________________________________________________________________________ 3

Note 1: Parts are 100% tested at +25°C. Limits across the full temperature range are guaranteed by design and correlation over the

specified temperature range.

Note 2: The dropout voltage is measured from V

IN

to V

OUT

when V

OUT

is 2% below its nominal value. The nominal output voltage is

measured from V

OUT

to GND when VINis 1V greater than V

OUT

. Defined only for V

OUT

≥ 2.5V.

Note 3: Soft-start time is defined as the time required for the output to rise from 10% of its nominal value to 90% of its nominal value.
Note 4: For V

OUT

< 2V, VINmust be above 2.5V.

Note 5: This is the maximum time OUT can be out of tolerance before a reset is issued. It is implemented to ensure that momentary

output glitches do not trigger a reset condition.

Note 6: In startup mode, the blanking time counter is not started until the soft-start time has elapsed. The total time from startup to

FLAG issued is t

SS

+ t

BLANK

.

ELECTRICAL CHARACTERISTICS (continued)

(VIN= V

OUT

+ 1V, SHDN = IN, C

OUT

= 3.3µF, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)

RESET OUTPUT (MAX4837)

RESET Threshold V

OUT Drop to RESET Delay
(Note 5)

RESET Timeout Period t

RESET Output-Voltage Low

RESET Output-Voltage High

FLAG OUTPUT (MAX4836)

Blanking Time (Note 6) t
Open-Drain FLAG Output-

Voltage Low

Open-Drain FLAG Leakage
Current

THERMAL PROTECTION

Thermal-Shutdown Temperature Junction temperature rising +165 °C

Thermal-Shutdown Hysteresis 15 °C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

RESET

t

OR

RESET

BLANK

0.85 x
V

D1 timing option 2.5 3.75 5.0

D2 timing option 20 30 40

D3 timing option 150 225 300

D4 timing option 1200 1800 2400

V

≥ 1.0V, I

OUT

V

≥ 1.5V, I

OUT

asserted

V

≥ 2.0V, I

OUT

RESET deasserted

V

+ 1V ≤ VIN ≤ 5.5V, OUT = GND 5 10 17 ms

OUT

I

= 3.2mA, FLAG asserted, V

SINK

V

= 5.5V 0.01 1 µA

FLAG

= 50µA, RESET asserted 0.3

SINK

= 3.2mA, RESET

SINK

SOURCE

≤ 500µA,

≥ 1.5V 0.4 V

OUT

0.8 x

V

OUT

OUT

0.875 x
V

0.90 x
V

OUT

35 µs

OUT

0.4

V

ms

V

V

MAX4836/MAX4837

500mA LDO Linear Regulators with
Current-Limiting Switch

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VIN= V

OUT

+ 1V, SHDN = IN, C

OUT

= 3.3µF, TA= +25°C, unless otherwise noted.)

QUIESCENT CURRENT vs. INPUT VOLTAGE

(NO LOAD)

MAX4836 toc01

VIN (V)

I

Q

(µA)

54321

20

40

60

80

100

120

0

06

TA = +85°C

TA = -40°C

TA = +25°C

V

OUT

= 1.5V

QUIESCENT CURRENT vs. INPUT VOLTAGE

(500mA LOAD)

MAX4836 toc02

VIN (V)

I

Q

(µA)

5432106

TA = +85°C

V

OUT

= 3.3V

TA = -40°C

100

200

300

400

500

600

700

800

0

TA = +25°C

MAXIMUM TRANSIENT DURATION

vs. RESET THRESHOLD OVERDRIVE

MAX4836 toc03

RESET THRESHOLD OVERDRIVE (mV)

PULSE DURATION (µs)

10

15

30

45

60

75

90

0

1100

RESET ASSERTS
ABOVE THIS LINE

VIN = 3.5V

V

OUT

= 2.5V

DROPOUT VOLTAGE vs. LOAD CURRENT

MAX4836 toc04

LOAD CURRENT (mA)

DROPOUT VOLTAGE (mV)

400300200100

30

60

90

120

150

180

0

0500

V

OUT

= 3.3V

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

MAX4836 toc05

FREQUENCY (kHz)

PSRR (dB)

1010.1

-70

-60

-50

-40

-30

-20

-10

0

-80

0.01 100

V

OUT

= 2V

C

OUT

= 3.3µF

I

LOAD

= 20mA

REGION OF STABLE C

OUT

ESR

vs. LOAD CURRENT

MAX4836 toc06

LOAD CURRENT (mA)

C

OUT

ESR (Ω)

1

2

3

4

5

6

7

0

V

OUT

= 1.8V

C

OUT

= 3.3µF

STABLE REGION

450400350300250200150100500500

OUTPUT NOISE vs. FREQUENCY

MAX4836 toc07

FREQUENCY (Hz)

OUTPUT NOISE (µV

RMS

)

10k1k100

10

20

30

40

50

0

10 100k

VIN = 3V
V

OUT

= 1.8V

C

SS

= 10nF

I

LOAD

= 0

SOFT-START RESPONSE

(C

SS

= FLOATING)

MAX4836 toc08

V

SS

1V/div

V

OUT

2V/div

V

IN

2V/div

2ms/div

t

SS

_______________________________________________________________________________________ 5

MAX4836/MAX4837

500mA LDO Linear Regulators with

Current-Limiting Switch

SOFT-START RESPONSE

(C

SS

= 0.01µF)

MAX4836 toc09

V

SS

1V/div

V

OUT

2V/div

V

IN

2V/div

2ms/div

t

SS

SOFT-START RESPONSE

(C

SS

= 0.1µF)

MAX4836 toc10

V

IN

2V/div

V

SS

1V/div

V

OUT

2V/div

20ms/div

t

SS

LOAD-TRANSIENT RESPONSE

MAX4836 toc11

V

OUT

50mV/div
AC-COUPLED

100µs/div

VIN = 4.3V
V

OUT

= 3.3V

C

IN

= 0.1µF

C

OUT

= 3.3µF

I

LOAD

: STEP FROM 10mA TO 100mA

BACK TO 10mA

LOAD-TRANSIENT RESPONSE

NEAR DROPOUT

MAX4836 toc12

V

OUT

50mV/div
AC-COUPLED

100µs/div

VIN = 3.4V
V

OUT

= 3.3V

C

IN

= 0.1µF

C

OUT

= 3.3µF

I

LOAD

: STEP FROM 10mA TO 100mA

BACK TO 10mA

LINE-TRANSIENT RESPONSE

MAX4836 toc13

V

OUT

50mV/div
AC-COUPLED

100µs/div

CIN = 0.1µF
C

OUT

= 3.3µF

V

OUT

= 3.3V

I

LOAD

= 10mA

5V
V

IN

500mV/div

4.5V

RESET RESPONSE TO V

IN

MAX4836 toc14

V

RESET

2V/div

V

OUT

2V/div

V

IN

2V/div

40ms/div

t

RESET

CSS = FLOATING

RESET RESPONSE TO V

OUT

MAX4836 toc15

V

RESET

1V/div

V

OUT

1V/div

40ms/div

t

RESET

VIN = 3.5V, CSS = FLOATING

RESET RESPONSE TO SHUTDOWN

MAX4836 toc16

V

RESET

2V/div

V

OUT

2V/div

V

SHDN

2V/div

40ms/div

t

RESET

VIN = 3.5V, CSS = FLOATING

Typical Operating Characteristics (continued)

(VIN= V

OUT

+ 1V, SHDN = IN, C

OUT

= 3.3µF, TA= +25°C, unless otherwise noted.)

MAX4836/MAX4837

500mA LDO Linear Regulators with
Current-Limiting Switch

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VIN= V

OUT

+ 1V, SHDN = IN, C

OUT

= 3.3µF, TA= +25°C, unless otherwise noted.)

FLAG RESPONSE WHEN OUT IS

SHORTED TO GND < BLANKING TIME

MAX4836 toc17

V

OUT

2V/div

1ms/div

I

OUT

200mA/div

V

FLAG

5V/div

FLAG RESPONSE WHEN OUT IS

SHORTED TO GND > BLANKING TIME

(IN IS TOGGLED)

MAX4836 toc18

V

OUT

1V/div

10ms/div

V

IN

2V/div

V

FLAG

2V/div

FLAG CONNECTED TO LOGIC SUPPLY

t

BLANK

STARTUP IN AN OVERLOAD CONDITION

(C

SS

NOT CONNECTED)

MAX4836 toc20

V

SS

1V/div

V

FLAG

2V/div

V

OUT

2V/div

2ms/div

t

BLANK

V

IN

2V/div

t

SS

V

OUT

= 2.5V

I

LOAD

= I

LIMIT

MAXIMUM

FLAG CONNECTED TO LOGIC SUPPLY

STARTUP IN AN OVERLOAD CONDITION

(C

SS

= 0.01µF)

MAX4836 toc21

V

SS

1V/div

V

FLAG

2V/div

V

OUT

2V/div

4ms/div

t

BLANK

V

IN

2V/div

t

SS

V

OUT

= 2.5V

I

LOAD

= I

LIMIT

MAXIMUM

FLAG CONNECTED TO LOGIC SUPPLY

NORMALIZED OUTPUT VOLTAGE

vs. TEMPERATURE

MAX4836 toc22

TEMPERATURE (°C)

NORMALIZED OUTPUT VOLTAGE

603510-15

0.996

0.998

1.000

1.002

1.004

0.994

-40 85

NORMALIZED TO +25°C

I

LOAD

= 500mA

I

LOAD

= 300mA

I

LOAD

= 100mA

FLAG RESPONSE WHEN OUT IS

SHORTED TO GND > BLANKING TIME

(SHDN IS TOGGLED)

MAX4836 toc19

V

OUT

1V/div

10ms/div

V

SHDN

2V/div

V

FLAG

2V/div

FLAG CONNECTED TO LOGIC SUPPLY

t

BLANK

Detailed Description

The MAX4836/MAX4837 are ultra-low quiescent current,
low-dropout linear regulators with an integrated current
limiter. These devices guarantee up to 500mA drive
capabilities and regulate the preset output voltage.

The MAX4836 has a flag output that asserts low when
the load current exceeds the current limit for more than
the blanking time (t

BLANK

). The MAX4837 has a reset
output that asserts low when the regulator output volt­age is below the reset threshold voltage (V

RESET

).

V

RESET

is 87.5% of the nominal output voltage. Figure 1
shows the simplified functional diagram and Figure 2
shows the typical application circuits.

FLAG

Output (MAX4836)

The open-drain FLAG output goes low and the LDO’s
pass transistor is latched off when the current in the
pass transistor is at its output current limit for more than
the blanking time (t

BLANK

). Cycling IN or SHDN (high to

low to high) brings the device out of its latched-off state
and back into normal operation.

RESET

Output (MAX4837)

The RESET output asserts when one of the following
conditions occurs:

• The input voltage (VIN) is below the input undervolt­age lockout threshold (V

UVLO

).

• The output voltage (V

OUT

) is below the reset thresh-

old (V

RESET

).

• SHDN is pulled low.

• The device is in thermal shutdown.

• When V

OUT

> V

IN.

RESET remains low for the reset timeout period (t

RESET

)

after reset conditions are terminated. There are four
RESET timeout periods available as shown in the
Electrical Characteristics table. RESET is available in a
push-pull configuration as shown in the Selector Guide.

Shutdown

Pull SHDN low to shut down the LDO and reduce the
quiescent current consumption of the device from 90µA
to 0.1µA. In shutdown mode, the pass transistor, con­trol circuit, and reference circuit are turned off. Connect
SHDN to a supply voltage greater than VIHto turn on
the LDO.

MAX4836/MAX4837

500mA LDO Linear Regulators with

Current-Limiting Switch

_______________________________________________________________________________________ 7

Pin Description

PIN

SOT23 TDFN

11 IN

2 2 GND Ground

33SHDN

44

55 SS

6 6 OUT

—EP EP

NAME FUNCTION

FLAG

(MAX4836)

RESET

(MAX4837)

Regulator Power Input. Bypass IN to GND with a 0.1µF ceramic capacitor. Install the bypass
capacitor as close to the device as possible.

Active-Low Shutdown Input. Drive SHDN low to shutdown the regulator. Drive SHDN high or
connect to IN for normal operation.

Overcurrent Flag. Open-drain FLAG goes low when the device senses sustained current
exceeding the current-limit threshold for a duration longer than the blanking time. FLAG is high
when SHDN is low or the device is in thermal shutdown.

Active-Low Reset Output. Push-pull RESET goes low when the voltage at OUT is below the reset
threshold or when the voltage at OUT is greater than IN. RESET is low when SHDN is low or the
device is in thermal shutdown. After the reset condition terminates, RESET remains low for the
duration of the reset timeout period.

Soft-Start Control. Connect a capacitor, C
startup. No capacitor from SS to GND gives 1ms output rise time at startup. See the soft-start
response time plots in the Typical Operating Characteristics.

Regulator Output. Bypass OUT to GND with a 3.3µF or larger ceramic capacitor. The capacitor’s
ESR should be less than 0.2Ω for stable operation.

Exposed Pad. EP is internally connected to GND. Externally connect EP to GND to provide a low
thermal resistance path from the IC junction to the PC board.

, from SS to GND to program the output rise time at

SS

MAX4836/MAX4837

500mA LDO Linear Regulators with
Current-Limiting Switch

8 _______________________________________________________________________________________

Figure 1. Functional Diagram

Figure 2. Typical Application Circuits

THERMAL

PROTECTION

MAX4836/MAX4837

IN

OVERLOAD

PROTECTION

SHDN

REVERSE-

CURRENT

PROTECTION

RESET
(FLAG)

( ) MAX4836E_ _xyC ONLY.

RESET TIMEOUT

(BLANKING PERIOD)

PASS

TRANSISTOR

V

REF

V

FB

ERROR

AMPLIFIER

1.23V

SWITCH OPEN

DURING SOFT-START

V

REF

WHEN SOFT-START

GND

V

SS

VSS = V

REF

IS COMPLETE

v

FB

90% x V

MAX4837 ONLY

900Ω

SWITCH

CLOSED IN

SHUTDOWN

V

REF

REF

1nF

1.23µA

V

OUT

SS

SS

GND

OUT

C

OUT

3.3µF
LOAD

2.5V TO 5.5V

C

0.1µF

IN

IN

OUT

MAX4837

SS

C

SS

TO µC

ON

OFF

RESET

SHDN

SS

GND

2.5V TO 5.5V

0.1µF

C

IN

TO µC

OFF

IN

V

LOGIC

MAX4836

FLAG

ON

SHDN

C

OUT

3.3µF

C

SS

LOAD

Shutdown Discharge (MAX4837)

OUT discharges through a 900Ω internal resistor during
shutdown mode.

Reverse OUT to IN Current

When the output voltage is greater than the input volt­age, the internal pass transistor turns off. To avoid
reverse-charging the input source, the current at IN is
guaranteed to be below 3µA when V

OUT

≥ VIN.

Current Limit

The MAX4836/MAX4837 include an accurate internal
current-limiting circuit. OUT can be shorted to ground
indefinitely without damaging the part.

The MAX4836 latches off if the load current exceeds the
current limit for more than the blanking time (see the

FLAG

Output section). During soft-start, the device does
not latch off to an overload condition. During an overload
condition, the MAX4837 holds the current at current limit
until the thermal limit is reached. Once the junction tem­perature reaches +165°C, thermal shutdown occurs.

Thermal Shutdown

When the junction temperature (TJ) exceeds +165°C,
the LDO’s pass transistor turns off allowing the junction
to cool. The LDO’s pass transistor turns on again after
the IC’s junction temperature cools by 15°C, resulting in
a pulsed output during continuous thermal-overload
conditions.

Soft-Start

During power-up, the soft-start ensures that the output
ramps up slowly reducing inrush current peaks. See
the soft-start response time plots in the Typical
Operating Characteristics. The soft-start time (t

SS

) is

given by the following equation:

t

SS

= CSS(ms)

where CSSis in nF.

A soft-start capacitor (CSS) of 10nF gives a 10ms tSS. A
1ms minimum soft-start time is fixed internally to ensure
that the output rises slowly even without any external
capacitor at SS pin to ground. The device is in soft-start
mode when either the voltage at IN or SHDN is cycled
high to low to high.

Applications Information

Capacitor Selection and Regulator

Stability

For stable operation over the full temperature range and
with load currents up to 500mA, use a 3.3µF (min)
ceramic output capacitor with an ESR <0.2Ω. To reduce
noise and improve load transient response, stability, and
power-supply rejection, use larger output capacitor
values such as 10µF (note that some ceramic capacitors
exhibit large capacitance and ESR variation with temper­ature). X7R capacitors provide good performance over
the -40°C to +85°C operating temperature range.

To improve power-supply rejection and transient
response, use a 0.1µF capacitor between IN and GND.
The MAX4836/MAX4837 remain stable with purely
resistive loads or current loads up to 500mA.

15kV Operational ESD Protection

A 3.3µF or higher value ceramic capacitor from OUT to
GND provides a 15kV (Human Body Model) protection
at OUT. The ESR value of the capacitor should be less
than 0.2Ω.

Reset Transient Immunity

The reset circuit is relatively immune to short duration,
falling V

OUT

transients. The Typical Operating
Characteristics show a graph of the Maximum Transient
Duration vs. Reset Threshold Overdrive for which reset is
not asserted. The graph was produced using falling V

OUT

transients starting at V

OUT

and ending below the reset
threshold by the magnitude indicated (reset threshold
overdrive). The graph shows the maximum pulse width
that a falling V

OUT

transient can typically have without
triggering the reset pulse. As the amplitude of the tran­sient increases (i.e., goes further below the reset thresh­old), the maximum allowable pulse width decreases.
Typically, a V

OUT

transient that goes only 10mV below the
reset threshold and lasts up to 54µs does not trigger a
reset pulse.

Layout

When using the TDFN package, connect its exposed
paddle to GND to provide a low thermal resistance
path for heat transfer from the IC junction to the printed
circuit board.

MAX4836/MAX4837

500mA LDO Linear Regulators with

Current-Limiting Switch

_______________________________________________________________________________________ 9

MAX4836/MAX4837

500mA LDO Linear Regulators with
Current-Limiting Switch

10 ______________________________________________________________________________________

Selector Guide

Suffix ‘xy’ in the part number stands for nominal output voltage. 1.8V, 2.5V, 2.8V, 3.0V, 3.3V are the standard options. For other voltages
between 1.5V to 3.3V, contact factory.

Table 1. Standard Output Voltage Suffix
Guide

Nonstandard output voltages from 1.5V to 3.3V are available in
100mV increments. Contact factory for availability.

Table 2.

RREESSEETT

Timeout Period Suffix

Guide

Pin Configurations (continued)

Chip Information

TRANSISTOR COUNT: 1575

PROCESS: BiCMOS

TDFN Exposed Pad: Connected to GND

PART

MAX4836EUTxyC-T 6 SOT23-6 500 Open-Drain FLAG No Yes
MAX4836ETTxyC-T 6 TDFN-6 500 Open-Drain FLAG No Yes
MAX4837EUTxyBdd-T 6 SOT23-6 500 Push-Pull RESET Yes No
MAX4837ETTxyBdd-T 6 TDFN-6 500 Push-Pull RESET Yes No

PIN-

PACKAGE

xy OUTPUT VOLTAGE (V)

18 1.8

25 2.5

28 2.8

30 3.0

33 3.3

dd RESET TIMEOUT (ms)

D1 3.75

D2 30

D3 225

D4 1800

OUTPUT

CURRENT (mA)

RESET OUTPUT

CONFIGURATION

RESET

(FLAG)

TOP VIEW

1 6 OUT

IN

GND

SHDN

( ) MAX4836EUTxyC ONLY.

MAX4836/

2

MAX4837

34

SOT23

SHUTDOWN
DISCHARGE

5SS

RESET
(FLAG)

LATCH OFF

MAX4836/MAX4837

500mA LDO Linear Regulators with

Current-Limiting Switch

______________________________________________________________________________________ 11

Package Information

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages

.)

PIN 1
INDEX
AREA

D

E

A

NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY

DETAIL A

L

N

E2

C

L

e

C

L

L

e

PACKAGE OUTLINE, 6, 8, 10 & 14L,
TDFN, EXPOSED PAD, 3x3x0.80 mm

21-0137

6, 8, &10L, DFN THIN.EPS

1

F

2

COMMON DIMENSIONS

MIN. MAX.

SYMBOL

A 0.70 0.80

D 2.90 3.10

E 2.90 3.10

A1 0.00 0.05

L

A2 0.20 REF.

PACKAGE VARIATIONS

PKG. CODE

T833-1

T1033-1

0.40

0.20

0.25 MIN.k

N D2 E2 e

2.30±0.101.50±0.106T633-1 0.95 BSC MO229 / WEEA

1.50±0.10

2.30±0.108

1.50±0.10

1.70±0.10 2.30±0.1014T1433-1

1.70±0.10

0.65 BSC

2.30±0.1010

0.50 BSC

0.40 BSC

0.40 BSC

JEDEC SPEC

MO229 / WEEC

MO229 / WEED-3

- - - - 0.20±0.03 2.40 REFT1433-2 14 2.30±0.10

b

0.40±0.05

[(N/2)-1] x e

1.90 REF

1.95 REF0.30±0.05

2.00 REF0.25±0.05

2.40 REF0.20±0.03- - - -

PACKAGE OUTLINE, 6, 8, 10 & 14L,
TDFN, EXPOSED PAD, 3x3x0.80 mm

21-0137

2

F

2

MAX4836/MAX4837

500mA LDO Linear Regulators with
Current-Limiting Switch

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.

12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600

© 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

Package Information (continued)

(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages

.)

6LSOT.EPS

PACKAGE OUTLINE, SOT-23, 6L

1

21-0058

F

1