TAIWAN SEMICONDUCTOR TS809, TS810, TS809R, TS810R Technical data

TS809/810/809R/810R Series

Microprocessor Reset Circuit

1/7 Version: A07

SOT-23

General Description

The TS809/810 series are microprocessor (µP) supervisory circuit used to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V powered circuits. These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The TS809/810 series have push pull outputs. The TS809/809R have an active low RESET output, while the TS810/810R has an active high (RESET) output. The reset comparator is designed to ignore fast transients on VCC, and the output guaranteed to be in the correct logic state for VCC down to 1V. Low supply correct makes the TS809/810 series ideal for use in portable equipment.

Features

● Highly Accurate: ±2%

● Precision monitoring of +3V, +3.3V and +5V power

supply voltage

● Fully specified over temperature

● Available in three output configurations

● Push-Pull RESET low output (TS809/TS809R)

● Push-Pull (RESET) high output (TS810/TS810R)

● 140mS min. power-on reset pulse width

● 12uA supply current

● Guaranteed reset valid to Vcc = +1V

● Power supply transient immunity

● No external components

Ordering Information

Note: x is the threshold voltage type, option as A

: 4.63V

: 4.38V

: 4.00V

: 3.08V

: 2.93V

: 2.63V

: 2.32V

: 2.1V

: 2.0V

Part No.

Package

Packing

TS809CXx RF

SOT-23

3Kpcs / 7” Reel

TS810CXx RF

SOT-23

3Kpcs / 7” Reel

TS809RCXx RF

SOT-23

3Kpcs / 7” Reel

TS810RCXx RF

SOT-23

3Kpcs / 7” Reel

Applications

● Battery-operated systems

● Controllers

● Intelligent instruments

● Critical uP and uC power monitoring

● Portable / Battery powered equipment

● Automotive

Pin Descriptions

Name

Description

Gnd

Ground

RESET

(RESET)

RESET – TS809 / TS809R (Active Low) (RESET) – TS810 / TS810R (Active High)

Vcc

Operating voltage input

Application Circuit

Pin Definition:

TS809/TS810

TS809R/TS810R

1. Ground

1. RESET(RESET)

2. RESET(RESET)

2. Ground

3. Vcc

TS809/810/809R/810R Series

Microprocessor Reset Circuit

2/7 Version: A07

Absolute Maximum Rating

Parameter

Symbol

Maximum

Unit

Terminal Voltage (with respect to Gnd)

VCC 7 V

RESET & (RESET) push-pull

RESET

- 0.3 ~ (VCC +0.3)

Input Current, VCC

ICC

Output Current, RESET, (RESET)

Rate of Rise, VCC

100

V/uS

Continuous Power Dissipation

320

Operating Junction Temperature Range

OPR

-40 ~ +125

Storage Temperature Range

STG

-65 ~ +150

Lead Soldering Temperature (260oC)

LEAD

Electrical Specifications (Ta = 25

C, unless otherwise noted)

Parameter

Conditions

Symbol

Min

Typ

Max

Unit

Input Supply Voltage

Ta=-40oC~+85oC

VCC

1.0

5.5

VIN=VIN *1.10

3.0

Supply Current

VIN=VIN *1.10, Ta=-40oC~+85oC

ICC

5.0

TS809/809R/810/810RCXA

4.56

4.63

4.7

TS809/809R/810/810RCXB

4.31

4.38

4.45

TS809/809R/810/810RCXC

3.94

4.00

4.06

TS809/809R/810/810RCXD

3.03

3.08

3.13

TS809/809R/810/810RCXE

2.89

2.93

2.97

TS809/809R/810/810RCXF

2.59

2.63

2.67

TS809/809R/810/810RCXG

2.28

2.32

2.35

TS809CXH

2.07

2.1

2.13

Reset Threshold

TS809CXI

VTH

1.97

2.0

2.03

Reset Threshold Temperature Coefficient

160

ppm/

VCC to Reset Delay

VCC = VTH - 100mV

Reset Active Timeout Period

Ta=-40oC~+85oC

DELAY

140

210

500

RESET Output (TS809/R) Voltage Low

VCC < V

TH(MAX)

, I

SINK

=1.2mA

VOL

0.2

VCC > V

TH(MAX)

, I

SOURCE

=0.5mA,

VCC > 1.8V

RESET Output (TS809/R) Voltage High

VCC > V

TH(MAX)

, I

SOURCE

=0.15mA,

1.8V ≥ VCC >1.0V

VOH

0.8

VCC

(RESET) Output (TS810/R) Voltage Low

VCC > V

TH(MAX)

, I

SINK

=1.2mA

VOL

0.2

VCC < V

TH(MAX)

, I

SOURCE

=0.5mA,

VCC > 1.8V

(RESET) Output (TS810/R) Voltage High

VCC > V

TH(MAX)

, I

SOURCE

=0.15mA,

1.8V ≥ VCC >1.0V

VOH

0.8

VCC

TS809/810/809R/810R Series

Microprocessor Reset Circuit

3/7 Version: A07

Application Note

Function Description

A microprocessor’s (µP’s) reset input starts the µP In a know state. The TS809/810/809R/810R assert reset to prevent code-execution errors during power-up, power-down, or brownout conditions. They assert a reset signal whenever the Vcc supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after Vcc has risen above the reset threshold. The TS809/810/809R/810R have a push-pull output stage.

Applications Information

Negative-Going VCC transients in addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the TS809/810 are relatively immune to short-duration negative-going Vcc transients (glitches). The TS809/810/809R/810R do not generate a reset pulse. The graph was generated using a negative going pulse applied to Vcc, starting 0.5V above the actual reset threshold and ending below it by the magnitude indicated (reset comparator overdrive). The graph indicates the maximum pulse width a negative going Vcc transient can have without causing a reset pulse. As the magnitude of the transient increases (goes farther below the reset threshold), the maximum allowable pulse width decreases. Typically, a Vcc transient that goes 100mV below the reset threshold and lasts 20µS or less will not cause a reset pulse. A 0.1µF bypass capacitor mounted as close as possible to the Vcc pin provides additional transient immunity.

Ensuring a Valid Reset Output Down to Vcc=0

When Vcc falls below 1V, the TS809/810/809R/810R reset output no longer sinks current - it becomes an open circuit. Therefore, high impedance CMOS logic input connected to reset can drift to undetermined voltages. This present no problem in most applications since most µP and other circuitry is inoperative with Vcc below 1V.However, in applications where reset must be valid down to 0V, adding a pull down resistor to reset causes and stray leakage currents to flow to ground, holding reset low (Figure 2.) R1’s value is not critical; 100K is large enough not to load reset and small enough to pull RESET to ground. For the TS809/810/809R/810R if reset is required to remain valid for Vcc<1V.

Benefits of Highly Accurate Reset Threshold

Most µP supervisor ICs has reset threshold voltages between 5% and 10% below the value of nominal supply voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur when the supply is 10% below nominal. When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset many or may not be asserted

Timming Diagram

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