ISL88001, ISL88002, ISL88003

FN6174 Rev 3.00

Page 9 of 15

Feb 10, 2021

Pin Descriptions

RST

The ISL88003 push-pull RST output is set to VDD (HIGH)

whenever the device is first powered up or VDD falls below its

respective minimum voltage sense level.

RST

The RST output functions identically to the complementary

RST output. On the ISL88001, this is a push-pull output. On

the ISL88002, it is an open drain output that is pulled to GND

(LOW) when reset is asserted. Suggested pull-up RST resistor

values are in the range of 5kΩ to 100kΩ.

VDD

The VDD pin is the power supply terminal. The voltage at this

pin is compared against an internal factory-programmed

voltage trip point, VTHVDD. A reset is first asserted when the

device is initially powered up to ensure that the power supply

has stabilized. Thereafter, reset is again asserted whenever

VDD falls below VTHVDD. The device is designed with

hysteresis to help prevent chattering due to noise.

Principles of Operation

The ISL88001, ISL88002, ISL88003 devices provide a low

power, high accuracy solution for those voltage monitoring

applications needing supply voltage supervision with power

reset control. By integrating these features into small 3 Ld SC-

70 and 3 Ld SOT-23 packages and consuming as little as

160nA of supply current, these devices can lower system cost

and reduce board space requirements.

Low Voltage Monitoring

During normal operation, the ISL88001, ISL88002, ISL88003

devices monitor the voltage level of VDD. The device asserts a

reset signal (RST = LOW or RST = HIGH) to a µP/µC if this

voltage is less than the preset voltage trip point. The reset

signal prevents system operation during a power failure or

brownout condition. This reset signal remains asserted until

VDD exceeds the voltage threshold setting for the reset time

delay period tPOR. See Figure 2.

RESET / RESET

VOL

Reset Output Voltage Low

VDD < VTHVDD, for ISL88001

0.2

0.40

V

VDD < VTHVDD, Sinking 0.5mA for ISL88002

0.2

0.40

V

VDD VTHVDD, for ISL88003

0.2

0.40

V

VOH

Reset Output Voltage High

VDD > VTHVDD, for ISL88001

VDD - 0.4 VDD - 0.2

V

VDD > VTHVDD, Sourcing 0.5mA, ISL88002

VDD - 0.2

V

VDD < VTHVDD, for ISL88003

VDD - 0.4 VDD - 0.2

V

tRPD

VTH to Reset Asserted Delay

15

µs

tPOR

POR Timeout Delay

140

200

260

ms

CLOAD

Load Capacitance on Reset Pin

5

pF

NOTE:

8. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization

and are not production tested.

Electrical Specifications Over the recommended operating conditions unless otherwise specified. (Continued)Boldface limits apply

over the operating temperature range, -40°C to +85°C.

SYMBOL

PARAMETER

TEST CONDITIONS

MIN

(Note 8)

TYP

MAX

(Note 8) UNITS

ISL88001

RPU*

ISL88002*

FIGURE 1. TYPICAL APPLICATION DIAGRAM

GND

VDD

ISL88003

µP/µC

GND

VDD

VDD

RESET

INPUT

RESET

OUTPUT

*Necessary for ISL88002