Micrel, Inc.

MAX823/4/5

January 14, 2014

4

Revision 1.0

Pin Configuration

MAX823

SOT23(EUK) &SC70(EXK)

Top View

MAX824

SOT23(EUK) &SC70(EXK)

Top View

MAX825

SOT23(EUK) &SC70(EXK)

Top View

Pin Description

Pin Number

MAX823

Pin Number

MAX824

Pin Number

MAX825

Pin Name

Pin Function

1

1

1

/RESET

Active-Low Reset Output. Pulses low for 200ms when triggered, and

a logic low. It remains low for 200ms after one of the following occurs:

/MR goes low to high.

2

2

2

GND

Ground.

-

3

3

RESET

Active-High Reset Output. Pulses high for 200ms when triggered, and

is a logic low. It remains high for 200ms after one of the following

reset, or /MR goes low to high. RESET is the inverse of /RESET.

4

4

-

WDI

Watchdog Input. If WDI remains either high or low for longer than the

watchdog timeout period, the internal watchdog timer runs out and a

reset is triggered. The internal watchdog timer clears whenever reset

is asserted, or whenever WDI sees a rising or falling edge. If WDI is

left unconnected or is connected to a three-stated buffer output, the

watchdog feature is disabled.

3

-

4

/MR

Manual Reset Input. A logic low on /MR asserts reset. Reset remains

asserted as long as /MR is held low and for 200ms after /MR returns

high. The active-low input has an internal 52k

Ω pull-up resistor. It can

be driven from a CMOS logic line or shorted to ground with a switch.

Leave open or connect to VCC if unused.

5

5

5

VCC

Supply Voltage Pin. VCC is the input to the supply voltage monitor.

When the supply voltage falls below the reset threshold voltage, reset

outputs (/RESET and RESET) are triggered immediately. When the

supply voltage rises above the reset threshold plus hysteresis voltage,

the reset outputs remain asserted for the duration of the reset timeout

period. An optional 0.1µF bypass capacitor mounted close to VCC

provides additional transient immunity.