ST STM1001 User Manual

查询STM1001供应商

FEAT URES SUMMARY

■ PRECISION MONITORING OF 3V, 3.3V, and

5V SUPPLY VOLTAGES

■ OPEN DRAIN RST OUTPUT

■ 140ms RESET PULSE WIDTH (MIN)

■ LOW SUPPLY CURRENT - 6µA (TYP)

■ GUARANTEED RST ASSERT ION DOWN TO

= 1.0V

V

CC

■ OPERATING TEMPERAT UR E:

–40°C to 85°C (Industrial Grade)

■ LEAD-FREE, SMALL SOT 2 3 PACK AGE

STM1001

Reset Circuit

Figure 2. Package

SOT23-3 (WX)

Figure 1. Logic Diagram

V

CC

STM1001

V

SS

RST

AI09116

Table 1. Signal Names

V

SS

RST

V

CC

Ground
Active-Low RESET Output (Open

Drain)
Supply Voltage

Figure 3. SOT23-3 Connections

CC

1

3

2

AI09117

RST

V

V

SS

1/13November 2004

STM1001

TABLE OF CONTENTS

FEATURES SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 1. Logic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2. Package. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Table 1. Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 3. SOT23-3 Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

SUMMARY DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 4. Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Figure 5. Hardware Hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Reset Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Negativ e- Go in g V
Valid /RST Output Down to V

TYPICAL OPERATING CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 6. Supply Current vs. Temperature, L/M/R/S/T (no load) . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 7. Power-down Reset Delay vs. Temperature - V
Figure 8. Power-down Reset Delay vs. Temperature - V
Figure 9. Power-up t

Figure 10.Normalized Reset Threshold vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 11.Max Transient Duration NOT Causing Reset Pulse vs. Reset Comparator Overdrive . . . 7

Transients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

CC

= 0V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

CC

= VTH – VCC (L/M). . . . . . . . . . . . . . . .5

OD

= VTH – VCC (R/S/T) . . . . . . . . . . . . . . 6

OD

vs. Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

rec

MAXIMUM RATING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 2. Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

DC and AC PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 3. Operating and AC Measurement Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 12.AC Testing Input/Output Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Table 4. DC and A C Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

PACKAGE MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0

Figure 13.SOT23-3 – 3-lead Small Outline Transistor Package Outline. . . . . . . . . . . . . . . . . . . . . 10

Table 5. S OT 23-3 – 3-lead Small Outline Transi stor Package Mechani ca l Data . . . . . . . . . . . . . 10

PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 6. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 7. Marking Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

REVISION HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 8. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

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SUMMARY DESCRIPTION

The STM1001 MICROPR OCESSOR RESET Cir­cuit is a low-power supervisory device used to
monitor power supplies. It perf orms a sin gle func ­tion: asserting a reset signal whenever the V

Figure 4. Block Diagram

V

CC

Note: 1. Ope n Drain

AI09118

V

RST

COMPARE

Figure 5. Hardware Hookup

V

CC

CC

STM1001

supply voltage drops below a preset value and
keeping it asserted until V
preset threshold for a minimum period of time
(t

).

rec

t

rec

Generator

has risen ab ove the

CC

(1)

RST

Note: 1. RST output requires pull-up resistor.

V

CC

STM1001

RST

V

SS

V

MCU

RESET
Input

CC

V

SS

AI09119

(1)

(1)

3/13

STM1001

OPERATION

Reset Output

The STM1001 MICROPROCESSOR RESET
CIRCUIT asserts a reset signal to the MCU when­ever V
RST
70°C).

During power-up, once V
threshold an internal timer keeps RST
reset time-out period, t
returns high.

If V
low. Each time RST
least the reset time-out period. Any time V
below the reset threshold, the internal timer clears.
The reset timer starts when V
reset threshold. The active-low reset (RST
open drain output.

Negative-Going V

The STM1001 is relatively immune to negative-go­ing V
shows typical transient duration versus reset com­parator overdrive (for which the STM1001 will
NOT generate a reset pulse). The graph was gen­erated using a negative pulse applied to V
starting at 0.5V above the actual reset thre shold

goes below the reset threshold (V

CC

RST

is guaranteed valid down to VCC=1V (0° to

exceeds the reset

CC

low for the

. After this interval, RST

rec

drops below the reset threshold, RST goes

CC

is asserted, it stays low for at

goes

CC

returns above the

CC

) is an

Transients

CC

transients (glitches). Figure 11., page 7

CC

CC

and ending below it by the magnitude indicated
(comparator overdrive). The graph indicates the

).

maximum pulse width a negative V
can have without causing a reset pulse. As the
magnitude of the transient increases (further be­low the threshold), the maximum allowable pulse
width decreases. Any combination of duration and
overdrive which lies under the curve will NOT gen­erate a reset signal. Typically, a V

CC

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 V

Valid /RST Output Down to V

When V

pin provides additional transient immunity.

CC

= 0V

CC

falls below 1V, the RST output no long-

CC

er sinks current, but becomes an open circuit. In
most systems this is not a problem, as most MCUs
do not operate below 1V. However, in applications
where RST

output must be valid down to 0V, a
pull-down resistor may be added t o hold the RST
output low. This resistor must be large enough to
not load the RST
to pull the output to ground. A 100KΩ re sistor is

,

recommended.

output, and still be small enough

transient

CC

transient that

4/13