ST STM6905 User Manual

Quintuple, ultralow voltage supervisor

Features

■ Quintuple voltage monitoring

■ Accurate ±1.8% across temperature voltage

threshold (±1% at 25°C)

■ Primary supply (V

programmed) reset thresholds: 3.078 V to

2.866 V

■ Second fixed (V2IN) monitor. Fixed (factory-

programmed) reset thresholds: 2.333 V to

1.050 V

■ Three additional adjustable supply monitor

inputs (externally adjustable)

■ 600 mV internal reference

■ RST output (open drain)

■ Output guaranteed for V

■ Reset delay time (t

(typ)

■ Manual reset input (MR)

■ Low supply current of 12 µA (typ)

■ Power supply voltage 0.8 V to 5.5 V

■ RoHS compliant (green package)

■ 8-pin MSOP/TSSOP

■ Operating temperature: –40°C to 85°C

(industrial grade)

) monitor. Fixed (factory -

CC

≥ 0.8 V

CC

) on power-up: 210 ms

rec

STM6905

with push-button reset

MSOP8

(TSSOP8) (DS)

Applications

■ Set-top boxes

■ Multi-voltage systems

■ Cable/satellite applications

■ Computer systems

■ Data storage equipment

Table 1. Device summary

Order code V

(1)

(V) V

RST1

(V) t

RST2

(ms) Package

REC

STM6905TZEDS6F 3.078 2.333 210 MSOP8(TSSOP8)

STM6905TWEDS6F 3.078 1.683 210 MSOP8(TSSOP8)

STM6905TGEDS6F 3.078 1.110 210 MSOP8(TSSOP8)

STM6905SYEDS6F 2.955 2.188 210 MSOP8(TSSOP8)

STM6905SFEDS6F 2.955 1.050 210 MSOP8(TSSOP8)

STM6905PWEDS6F 2.866 1.683 210 MSOP8(TSSOP8)

1. Other reset threshold voltages and t
ST sales office for availability.

time-out periods are offered. Minimum order quantities may apply. Contact local

REC

January 2008 Rev 3 1/19

www.st.com

1

Contents STM6905

Contents

1 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1 Push-button reset input (MR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.2 V

2.3 V2IN second fixed voltage monitoring input . . . . . . . . . . . . . . . . . . . . . . . . 7

2.4 V

2.5 V3IN, V4IN, and V5IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.6 RST

primary supply voltage monitoring input . . . . . . . . . . . . . . . . . . . . . . . 7

CC

SS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

active-low, open drain reset output . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.1 Setting the adjustable voltage levels for V3IN, V4IN, and V5IN inputs . . . . 9

3.2 Power on reset (t

) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

REC

4 Voltage monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

5 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

6 DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

8 Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

9 Package marking information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

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STM6905 List of tables

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Table 2. Signal names and functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Table 3. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 4. DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 5. TSSOP 8-lead package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 6. Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 7. Marking description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 8. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3/19

List of figures STM6905

List of figures

Figure 1. Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2. MSOP/TSSOP-8 connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 3. Functional block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 4. Typical hardware hookup application diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 5. MR

Figure 6. Voltage monitoring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 7. TSSOP8, 3 x 3mm, package mechanical outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

timing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4/19

STM6905 Description

1 Description

The STM6905 supervisor is a low voltage/low supply current processor supervisor,
designed to monitor up to five system power supply voltages. This device is targeted at
applications such as set-top boxes (STBs), portable, battery-powered systems, networking
and communication systems.

The device supports a push-button type manual reset input (MR
monitors (V
(V

RST1

and V

and V2IN) have fixed (customer-selectable, factory-trimmed) thresholds

CC

). The other three voltage monitor inputs (V3IN, V4IN and V5IN) are

RST2

). Two of the five supply

monitored using externally adjustable threshold (600 mV internal reference) to meet specific
level requirements.

If any of the five monitored voltages drops below its factory-trimmed or adjustable
thresholds, or if the MR
low). Once asserted, RST
monitored supplies rise above their respective thresholds and MR
output logic state is valid for V

is asserted to logic low, the reset output RST is asserted (driven

is maintained Low for a minimum delay period (trec) after ALL

returns to High. Reset

greater than 0.8 V.

CC

The STM6905 is available in a standard 8-lead MSOP (TSSOP) package.

Figure 1. Logic diagram

V

CC

V2IN

V3IN

V4IN

V5IN

STM6905

RST

MR

V

Figure 2. MSOP/TSSOP-8 connections

MR

V

CC

V2IN

V

SS

1

2

3

4

5/19

SS

ai13970

8

7

6

5

RST

V5IN

V4IN

V3IN

ai13971

Description STM6905

Table 2. Signal names and functions

Pin Name Type Function

1MR

2VCCSupply

3 V2IN Input Second fixed threshold input monitor

4V

5 V3IN Input Adjustable third reset comparator input

6 V4IN Input Adjustable fourth reset comparator input

7 V5IN Input Adjustable fifth reset comparator input

8RST

SS

Input Active-low manual reset input with internal pull-up resistor

Primary supply voltage input and integrated fixed threshold under­voltage monitor

Supply Ground

Output Active-low open-drain reset output (10k ohm internal pull-up)

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