STM6905
Quintuple, ultralow voltage supervisor with push-button reset
Features
■Quintuple voltage monitoring
■Accurate ±1.8% across temperature voltage threshold (±1% at 25°C)
■Primary supply (VCC) monitor. Fixed (factory - programmed) reset thresholds: 3.078 V to 2.866 V
■Second fixed (V2IN) monitor. Fixed (factoryprogrammed) 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 VCC ≥ 0.8 V
■Reset delay time (trec) on power-up: 210 ms (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)
MSOP8 (TSSOP8) (DS)
Applications
■Set-top boxes
■Multi-voltage systems
■Cable/satellite applications
■Computer systems
■Data storage equipment
Order code |
VRST1 (V) |
VRST2 (V) |
tREC (ms) |
Package |
STM6905TZEDS6F |
3.078 |
2.333 |
210 |
MSOP8(TSSOP8) |
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STM6905TWEDS6F |
3.078 |
1.683 |
210 |
MSOP8(TSSOP8) |
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STM6905TGEDS6F |
3.078 |
1.110 |
210 |
MSOP8(TSSOP8) |
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STM6905SYEDS6F |
2.955 |
2.188 |
210 |
MSOP8(TSSOP8) |
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STM6905SFEDS6F |
2.955 |
1.050 |
210 |
MSOP8(TSSOP8) |
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STM6905PWEDS6F |
2.866 |
1.683 |
210 |
MSOP8(TSSOP8) |
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1. Other reset threshold voltages and tREC time-out periods are offered. Minimum order quantities may apply. Contact local ST sales office for availability.
January 2008 |
Rev 3 |
1/19 |
www.st.com
Contents |
STM6905 |
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Contents
1 |
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
5 |
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2 |
Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
7 |
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2.1 |
Push-button reset input |
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7 |
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(MR) |
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2.2 |
VCC primary supply voltage monitoring input . . . . . . . . . . . . . . . . . . . . . . . |
7 |
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2.3 |
V2IN second fixed voltage monitoring input . . . . . . . . . . . . . . . . . . . . . . . . |
7 |
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2.4 |
VSS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
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2.5 |
V3IN, V4IN, and V5IN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
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2.6 |
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active-low, open drain reset output |
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RST |
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3 |
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
9 |
3.1 Setting the adjustable voltage levels for V3IN, V4IN, and V5IN inputs . . . . 9 3.2 Power on reset (tREC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 |
Voltage monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
10 |
5 |
Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
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6 |
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
12 |
7 |
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
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8 |
Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
16 |
9 |
Package marking information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
17 |
10 |
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . |
18 |
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STM6905 |
List of tables |
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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
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List of figures |
STM6905 |
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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 timing waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 6. Voltage monitoring diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Figure 7. TSSOP8, 3 x 3mm, package mechanical outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
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STM6905 |
Description |
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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). Two of the five supply monitors (VCC and V2IN) have fixed (customer-selectable, factory-trimmed) thresholds
(VRST1 and VRST2). The other three voltage monitor inputs (V3IN, V4IN and V5IN) are 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 is asserted to logic low, the reset output RST is asserted (driven low). Once asserted, RST is maintained Low for a minimum delay period (trec) after ALL monitored supplies rise above their respective thresholds and MR returns to High. Reset output logic state is valid for VCC greater than 0.8 V.
The STM6905 is available in a standard 8-lead MSOP (TSSOP) package.
VCC
V2IN
V3IN
V4IN |
STM6905 |
RST |
V5IN
MR
VSS |
ai13970 |
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RST |
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MR |
1 |
8 |
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VCC |
2 |
7 |
V5IN |
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V2IN |
3 |
6 |
V4IN |
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VSS |
4 |
5 |
V3IN |
ai13971
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Description |
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STM6905 |
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Table 2. |
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Signal names and functions |
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Name |
Type |
Function |
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1 |
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Input |
Active-low manual reset input with internal pull-up resistor |
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MR |
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2 |
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VCC |
Supply |
Primary supply voltage input and integrated fixed threshold under- |
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voltage monitor |
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3 |
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V2IN |
Input |
Second fixed threshold input monitor |
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4 |
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VSS |
Supply |
Ground |
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5 |
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V3IN |
Input |
Adjustable third reset comparator input |
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6 |
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V4IN |
Input |
Adjustable fourth reset comparator input |
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7 |
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V5IN |
Input |
Adjustable fifth reset comparator input |
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8 |
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Output |
Active-low open-drain reset output (10k ohm internal pull-up) |
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RST |
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6/19