Diodes APX823, APX824, APX825A User Manual

APX823/APX824/APX825A

Description

The APX823/APX824/APX825A family of supervisors
provides circuit initialization and timing supervision, primarily
for DSP and processor-based systems.

During power-on,
V

becomes higher than 1.1V. Thereafter, the supply

CC

voltage supervisor monitors V
long as V

internal timer delays the return of the output to the inactive
state (high) to ensure proper system reset. The delay time, t
starts after VCC has risen above the threshold voltage V

When the supply voltage drops below the threshold voltage
V

, the output becomes active (low) again. No external

TH-

components are required. All the devices of this family have a
fixed-sense threshold voltage V

divider.
The APX823/APX825A devices incorporate a manual reset

input,
active. The APX824/APX825A devices include a high-level

output RESET. APX823/APX824/APX825A have a watchdog
timer that is periodically triggered by a positive or negative
transition at WDI. When the supervising system fails to
retrigger the watchdog circuit within the time-out interval,

ttout,
event also reinitializes the watchdog timer. Leaving WDI

unconnected disables the watchdog.
In applications where the input to the WDI pin may be active

(transitioning high and low) when the APX823/APX824/AP X8
25A asserting
not return to a non-reset state when the input voltage is

above Vt. The product spectrum is designed for supply
voltage of 2.5V, 3V, 3.3V and 5V. The circuits are available in
a SOT25 and SOT26 packages. The
APX823/APX824/APX825A devices are characterized for
operation over a temperature range of -40

remains below the threshold voltage V

CC

. A low level at MR causes

MR

becomes active for the time period td. This

RESET

RESET

Features

is asserted when supply voltage

RESET

and keeps

CC

set by an internal voltage

TH-

RESET

the APX823/APX824/APX825A does

o

C to 105oC.

RESET

to become

active as

TH-

. An

TH-

d

.

PROCESSOR SUPERVISORY CIRCUITS

Pin Assignments



RESET

GND

MR



RESET

GND

RESET



RESET

GND

RESET

(Top View)

1

APX8 232

2

3 4

SOT25

(Top View)

1

2

2

APX824

3 4

SOT25

(Top View)

1
2

2

APX825A

3 4

SOT26

5

V

CC

WDI

5

V

CC

WDI

6

V

CC

5

WDI

MR

Applications

• Power-on reset generator with fixed delay time of 200ms

Typ

• Manual reset input (APX823/APX825A)

• Reset output available in active-low

(APX823/APX824/APX825A), active-high
(APX824/APX825A)

• Supply voltage supervision range 2.5V, 3V, 3.3V, 5V

• Watchdog timer

• Supply current of 30μA (Typ.)

• Temperature range: -40°C to 85°C

• SOT25 and SOT26: Available in “Green” Molding

Compound (No Br, Sb)

• Lead Free Finish/RoHS Compliant (Note 1)

Note: 1. EU Directive 2002/95/EC (RoHS). All applicable RoHS exemptions applied, see EU Directive 2002/95/EC Annex Notes.

• Applications Using DSPs, Microcontrollers, or

Microprocessors

• Industrial Equipment

• Programmable Controls

• Automotive Systems

• Portable/Battery-Powered Equipment

• Intelligent Instruments

• Wireless Communications Systems

• Notebook/Desktop Computers

APX823/APX824/APX825A

Document number: DS31323 Rev. 4 - 2

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© Diodes Incorporated

Typical Application Circuit

APX823/APX824/APX825A

PROCESSOR SUPERVISORY CIRCUITS

V

CC

C

IN

V

CC

100nF

V

CC

Pin Descriptions

Pin Name Description

GND Ground

RESET

(RESET)

Reset output pin

VCC

WDI Watchdog input

MR

Operating voltage input

Manual reset

Functional Block Diagram

RESET

APX8XX Microprocessor

MR WDI

GND

RESET

I/O

GND

APX823/APX824/APX825A

Document number: DS31323 Rev. 4 - 2

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APX823/APX824/APX825A

×

Absolute Maximum Ratings (Over operating ambient temperature range, unless otherwise noted)*

Symbol Parameter Rating Unit

ESD HBM Human Body Model ESD Protection 5 KV

ESD MM Machine Model ESD Protection 200 V

VCC

V

RESET

ICC Input Current VCC

IO

PD

TOP
TST

* 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 under “recommended operating conditions” is no t implied. Exposure to absolute-
maximum-rated conditions for extended periods may affect device reliability.

Recommended Operating Conditions

Symbol Parameter Min Max Unit

VCC

VIN
VIH
VIL

Δt/ΔV

TA

TR VCC Rising Time (VCC = 0~VT)

Supply Voltage 6.0 V
RESET, RESET , MR , WDI

Maximum High Output Current 20 mA

Derating Factor Above
T

= 25oC

A

Continuous Total Power
Dissipation

Operating Junction Temperature Range -40 to 105 °C
Storage Temperature Range -65 to 150 °C

Supply Voltage 1.1 5.5 V
Input Voltage 0

High-level Input Voltage at
Low-level Voltage -

Input Transition Rise and Fall Rate at
Operating Ambient Temperature Range -40 85

TA = 25oC Power Rating

TA = 70oC Power Rating

TA = 85oC Power Rating

MR and WDI

MR or WDI

PROCESSOR SUPERVISORY CIRCUITS

-0.3 to (VCC+0.3)
20 mA

SOT25 6.2
SOT26 5.8
SOT25 500
SOT26 470
SOT25 220
SOT26 210
SOT25 125
SOT26 120

(VCC+0.3)

VCC

0.7

- 100 ns/V

- 100 V/ uS

- V

0.3×VCC

V

mW/°C

mW

mW

mW

V

V

o

C

APX823/APX824/APX825A

Document number: DS31323 Rev. 4 - 2

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APX823/APX824/APX825A

×

Electrical Characteristics (Over recommended operating ambient temperature range, unless otherwise noted)

Symbol Parameter Test Conditions Min Typ. Max Unit

APX823/APX824/APX825A ­29/26/23

RESET

High-level

VOH

Output Voltage

RESET

RESET

Low-level

VOL

Output Voltage

RESET

V

RESET

Power-up Reset Voltage (see Note 2)

Negative-going

V

Input Threshold

TH-

Voltage
(see Note 3)

Note: 2. The lowest supply voltage at which

3. To ensure best stability of the threshold voltage, a bypass capacitor (ceramic, 0.1μF) should be placed near the supply terminals.

APX823/APX824/APX825A ­40/31

APX823/APX824/APX825A
–46/44

APX824/APX825A

-29/26/23
APX824/APX825A -

46/44/40/31
APX824/APX825A

-29/26/23

APX824/APX825A -46/44
APX823/APX824/APX825A -

29/26/23
APX823/APX824/APX825A -

40/31
APX823/APX824/APX825A -

46/44

APX823/APX824/APX825A -23
APX823/APX824/APX825A -26 2.59 2.63 2.69
APX823/APX824/APX825A -29 2.88 2.93 3.00
APX823/APX824/APX825A -31 3.02 3.08 3.15
APX823/APX824/APX825A -40 3.93 4.00 4.08
APX823/APX824/APX825A -44 4.31 4.38 4.47
APX823/APX824/APX825A -46 4.56 4.63 4.72
APX823/APX824/APX825A -23
APX823/APX824/APX825A -26 2.57 2.63 2.69
APX823/APX824/APX825A -29 2.86 2.93 3.00
APX823/APX824/APX825A -31 3.00 3.08 3.15
APX823/APX824/APX825A -40 3.92 4.00 4.08
APX823/APX824/APX825A -44 4.29 4.38 4.47
APX823/APX824/APX825A -46 4.54 4.63 4.72

becomes active. TR , VCC > 15μs/V.

RESET

PROCESSOR SUPERVISORY CIRCUITS

= V

TH-

= V

TH-

= V

TH-

=-120μA

> 1.8V,

= -100μA

> 1.8V,

= -150μA

= V

TH-

=1mA

= V

TH-

=1.2mA

= V

TH-

TH-

= V

TH-

=1.2mA

= V

TH-

+0.2V

+0.2V

+0.2V

+0.2V

+0.2V

+0.2V

-0.2V

-0.2V

-0.2V

0.8×VCC

VCC-1.5V

VCC

0.8

- - V

- - V

- - V

- - 0.4 V APX824/APX825A -40/31

- - 0.4 V

- - 0.4 V

2.21 2.25 2.30

V

2.20 2.25 2.30

V

V

CC

IOH=-20μA
V

CC

IOH=-30μA
V

CC

I

OH

V

CC

I

OH

V

CC

I

OH

V

CC

I

OL

V

CC

I

OL

V

CC

IOL=3mA
VCC= V
IOL=1mA
V

CC

I

OL

V

CC

IOL=3mA
VCC > 1.1V,
IOL=20μA

= 0oC -85oC

T

A

= -40oC -85oC

T

A

APX823/APX824/APX825A

Document number: DS31323 Rev. 4 - 2

4 of 12

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May 2011

© Diodes Incorporated