STM706T/S/R, STM706P,
STM708T/S/R
3 V supervisor
Datasheet - production data
Features
• Precision VCC monitor
– T: 3.00 V ≤ VRST ≤ 3.15 V
– S: 2.88 V ≤ VRST ≤ 3.00 V
– R: STM706P: 2.59 V ≤ VRST ≤ 2.70 V
• RST and RST outputs
• 200 ms (typ.) trec
• Watchdog timer - 1.6 s (typ.)
620
• Manual reset input (MR)
• Power-fail comparator (PFI/PFO)
• Low supply current - 40 µA (typ.)
• Guaranteed RST (RST) assertion down to
VCC = 1.0 V
• Operating temperature: –40 °C to 85 °C
(industrial grade)
• RoHS compliance
– Lead-free components are compliant with
the RoHS directive
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&RQWDFWORFDO67VDOHVRIILFHIRUDYDLODELOLW\
Applications
• Computers
• Controllers
• Intelligent instruments
Table 1. Device summary
STM706T/S/R
STM706P
(2)
Watchdog
input
Watchdog
output(1)
Active low
RST (1)
✓
✓
✓
✓
✓
STM708T/S/R
✓
Active high
RST(1)
Manual
reset input
Power-fail
comparator
✓
✓
✓
✓
✓
✓
✓
✓
1. Push-pull output.
2. The STM706P device is identical to the STM706R device, except its reset output is active high.
December 2015
This is information on a product in full production.
DocID10518 Rev 13
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www.st.com
Contents
STM706T/S/R, STM706P, STM708T/S/R
Contents
1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
Pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3
2.1
MR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.2
WDI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3
WDO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4
RST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.5
RST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.6
PFI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.7
PFO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1
Reset output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3.2
Push-button reset input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
3.3
Watchdog input (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . .11
3.4
Watchdog output (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . .11
3.5
Power-fail input/output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.6
Ensuring a valid reset output down to VCC = 0 V . . . . . . . . . . . . . . . . . . . 12
3.7
Interfacing to microprocessors with bi-directional reset pins . . . . . . . . . . 13
4
Typical operating characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
6
DC and AC parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
7
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
7.1
SO8 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.2
TSSOP8 3x3 (DS) package information . . . . . . . . . . . . . . . . . . . . . . . . . . 28
8
Part numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
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STM706T/S/R, STM706P, STM708T/S/R
List of tables
List of tables
Table 1.
Table 2.
Table 3.
Table 4.
Table 5.
Table 6.
Table 7.
Table 8.
Table 9.
Table 10.
Table 11.
Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Signal names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Operating and AC measurement conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
DC and AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
SO8 - 8-lead plastic small outline, 150 mils body width, mechanical data . . . . . . . . . . . . . 27
TSSOP8 - 8-lead, thin shrink small outline, 3 x 3 mm body size,
mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Marking description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
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3
List of figures
STM706T/S/R, STM706P, STM708T/S/R
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Figure 15.
Figure 16.
Figure 17.
Figure 18.
Figure 19.
Figure 20.
Figure 21.
Figure 22.
Figure 23.
Figure 24.
Figure 25.
Figure 26.
Figure 27.
Figure 28.
Figure 29.
Figure 30.
4/32
Logic diagram (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Logic diagram (STM708T/S/R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
STM706T/S/R and STM706P SO8 connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
STM706T/S/R and STM706P TSSOP8 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
STM708T/S/R SO8 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
STM708T/S/R TSSOP8 connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Block diagram (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Block diagram (STM708T/S/R) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Hardware hookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Reset output valid to ground circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Interfacing to microprocessors with bi-directional reset I/O . . . . . . . . . . . . . . . . . . . . . . . . 13
Supply current vs. temperature (no load) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
VPFI threshold vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Reset comparator propagation delay vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Power-up trec vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Normalized reset threshold vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Watchdog timeout period vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
PFI to PFO propagation delay vs. temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Output voltage vs. load current (VCC = 5 V; TA = 25 °C) . . . . . . . . . . . . . . . . . . . . . . . . . . 18
RST output voltage vs. supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
RST output voltage vs. supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Power-fail comparator response time (assertion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Power-fail comparator response time (de-assertion) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Maximum transient duration vs. reset threshold overdrive . . . . . . . . . . . . . . . . . . . . . . . . . 20
AC testing input/output waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Power-fail comparator waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
MR timing waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Watchdog timing (STM706T/S/R and STM706P) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
SO8 - 8-lead plastic small outline, 150 mils body width, package outline. . . . . . . . . . . . . . 27
TSSOP8 - 8-lead, thin shrink small outline, 3 x 3 mm body size, package outline . . . . . . . 28
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STM706T/S/R, STM706P, STM708T/S/R
1
Description
Description
The STM70x supervisors are self-contained devices which provide microprocessor
supervisory functions. A precision voltage reference and comparator monitors the VCC input
for an out-of-tolerance condition. When an invalid VCC condition occurs, the reset output
(RST) is forced low (or high in the case of RST).
These devices also offer a watchdog timer (except for STM708T/S/R) as well as a power-fail
comparator to provide the system with an early warning of impending power failure.
The STM706P device is identical to the STM706R device, except its reset output is active
high. These devices are available in a standard 8-pin SOIC package or a space-saving 8pin TSSOP package.
Figure 1. Logic diagram (STM706T/S/R and STM706P)
VCC
WDI
MR
WDO
STM706T/S/R,
STM706P
RST (RST)(1)
PFO
PFI
VSS
AI08841
1. For STM706P only.
Figure 2. Logic diagram (STM708T/S/R)
VCC
RST
MR
STM708T/S/R
RST
PFI
PFO
VSS
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Description
STM706T/S/R, STM706P, STM708T/S/R
Table 2. Signal names
Symbol
Name
MR
Push-button reset input
WDI
Watchdog input
WDO
Watchdog output
RST
Active low reset output
RST
(1)
Active high reset output
VCC
Supply voltage
PFI
Power-fail input
PFO
Power-fail output
VSS
Ground
NC
No connect
1. For STM706P and STM708T/S/R only.
Figure 3. STM706T/S/R and STM706P SO8 connections
SO8
MR
1
8
VCC
VSS
2
7
3
6
WDI
PFI
4
5
PFO
WDO
RST(RST)(1)
AI08837
1. For STM706P reset output is active high.
Figure 4. STM706T/S/R and STM706P TSSOP8 connections
TSSOP8
(1)
RST(RST)
1
8
WDI
WDO
2
7
PFO
MR
3
6
PFI
VCC
4
5
VSS
AI08838
1. For STM706P reset output is active high.
Figure 5. STM708T/S/R SO8 connections
SO8
MR
1
8
RST
VCC
VSS
2
7
RST
3
6
NC
PFI
4
5
PFO
AI08839
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Description
Figure 6. STM708T/S/R TSSOP8 connections
TSSOP8
RST
1
8
NC
RST
2
7
PFO
MR
3
6
PFI
VCC
4
5
VSS
AI08840
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31
Pin descriptions
2
Pin descriptions
2.1
MR
STM706T/S/R, STM706P, STM708T/S/R
A logic low on MR asserts the reset output. Reset remains asserted as long as MR is low
and for trec after MR returns high. This active low input has an internal pull-up. It can be
driven from a TTL or CMOS logic line, or shorted to ground with a switch. Leave open if
unused.
2.2
WDI
If WDI remains high or low for 1.6 s, the internal watchdog timer runs out and reset (or
WDO) is triggered. The internal watchdog timer clears while reset is asserted or when WDI
sees a rising or falling edge.
The watchdog function can be disabled by allowing the WDI pin to float. This feature is
available for the “D” version only (see Section 8: Part numbering).
2.3
WDO
WDO goes low when a transition does not occur on WDI within 1.6 s, and remains low until
a transition occurs on WDI (indicating the watchdog interrupt has been serviced) or MR
input is asserted (goes low). WDO also goes low when VCC falls below the reset threshold;
however, unlike the reset output, WDO goes high as soon as VCC exceeds the reset
threshold. Output type is push-pull.
Note:
For those devices with a WDO output, a watchdog timeout will not trigger reset unless WDO
is connected to MR.
2.4
RST
Pulses low for trec when triggered, and stays low whenever VCC is below the reset
threshold or when MR is a logic low. It remains low for trec after either VCC rises above the
reset threshold, the watchdog triggers a reset, or MR goes from low to high.
2.5
RST
Pulses high for trec when triggered, and stays high whenever VCC is above the reset
threshold or when MR is a logic high. It remains high for trec after either VCC falls below the
reset threshold, the watchdog triggers a reset, or MR goes from high to low.
2.6
PFI
When PFI is less than VPFI, PFO goes low; otherwise, PFO remains high. Connect to
ground if unused.
8/32
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STM706T/S/R, STM706P, STM708T/S/R
2.7
Pin descriptions
PFO
When PFI is less than VPFI, PFO goes low; otherwise, PFO remains high. Output type is
push-pull. PFO pin is not supposed to be forced low by a processor. MR input is gated off
during the period PFO is forced low. Leave open if unused.
Table 3. Pin description
Pin
STM706P
STM706T/S/R
STM708T/S/R
Name
Function
SO8
TSSOP8
SO8
TSSOP8
SO8
TSSOP8
1
3
1
3
1
3
MR
Push-button reset input
6
8
6
8
—
—
WDI
Watchdog input
8
2
8
2
—
—
WDO
Watchdog output (push-pull)
—
—
7
1
7
1
RST
Active low reset output
7
1
—
—
8
2
RST
Active high reset output
2
4
2
4
2
4
VCC
Supply voltage
4
6
4
6
4
6
PFI
Power-fail input
5
7
5
7
5
7
PFO
Power-fail output (push-pull)
3
5
3
5
3
5
VSS
Ground
—
—
—
—
6
8
NC
No connect
Figure 7. Block diagram (STM706T/S/R and STM706P)
WDI
transitional
detector
WDI
VCC
WATCHDOG
TIMER
VRST
WDO
COMPARE
VCC
trec
generator
MR
RST (RST)(1)
PFI
VPFI
COMPARE
PFO
AI08829
1. For STM706P only
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31
Pin descriptions
STM706T/S/R, STM706P, STM708T/S/R
Figure 8. Block diagram (STM708T/S/R)
VCC
COMPARE
VRST
RST
VCC
trec
generator
MR
PFI
COMPARE
VPFI
RST
PFO
AI08830
Figure 9. Hardware hookup
Regulator
Unregulated
voltage
VIN
VCC
VCC
STM706T/S/R;
STM706P;
STM708T/S/R
0.1 μF
WDI(1)
R1
WDO(1)
To microprocessor IRQ
PFI
PFO
To microprocessor NMI
MR
RST
RST(2)
From microprocessor
R2
Push-button
To microprocessor reset
AI08843
1. For STM706T/S/R and STM706P devices
2. For STM706P and STM708T/S/R devices
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STM706T/S/R, STM706P, STM708T/S/R
3
Operation
3.1
Reset output
Operation
The STM70x supervisor asserts a reset signal to the MCU whenever VCC goes below the
reset threshold (VRST), a watchdog timeout occurs (if WDO is connected to MR), or when the
push-button reset input (MR) is taken low. RST is guaranteed to be a logic low (logic high for
STM706P and STM708T/S/R) for VCC < VRST down to VCC =1 V for TA = 0 °C to 85 °C.
During power-up, once VCC exceeds the reset threshold an internal timer keeps RST low for
the reset timeout period, trec. After this interval RST returns high.
If VCC drops below the reset threshold, RST goes low. Each time RST is asserted, it stays
low for at least the reset timeout period (trec). Any time VCC goes below the reset threshold
the internal timer clears. The reset timer starts when VCC returns above the reset threshold.
3.2
Push-button reset input
A logic low on MR asserts reset. Reset remains asserted while MR is low, and for trec (see
Figure 27) after it returns high. The MR input has an internal 40 kΩ pull-up resistor, allowing
it to be left open if not used. This input can be driven with TTL/CMOS-logic levels or with
open-drain / collector outputs. Connect a normally open momentary switch from MR to GND
to create a manual reset function; external debounce circuitry is not required. If MR is driven
from long cables or the device is used in a noisy environment, connect a 0.1 µF capacitor
from MR to GND to provide additional noise immunity. MR may float, or be tied to VCC when
not used.
3.3
Watchdog input (STM706T/S/R and STM706P)
The watchdog timer can be used to detect an out-of-control MCU. If the MCU does not
toggle the watchdog input (WDI) within tWD (1.6 s), the watchdog output pin (WDO) is
asserted. The internal 1.6s timer is cleared by either:
1.
a reset pulse, or
2.
by toggling WDI (high-to-low or low-to-high), which can detect pulses as short as 50 ns.
See Figure 28 for STM706T/S/R and STM706P.
The timer remains cleared and does not count for as long as reset is asserted. As soon as
reset is released, the timer starts counting.
Note:
The watchdog function may be disabled by floating WDI or tri-stating the driver connected to
WDI. When tri-stated or disconnected, the maximum allowable leakage current is 10 µA and
the maximum allowable load capacitance is 200 pF.
3.4
Watchdog output (STM706T/S/R and STM706P)
When VCC drops below the reset threshold, WDO will go low even if the watchdog timer has
not yet timed out. However, unlike the reset output, WDO goes high as soon as VCC
exceeds the reset threshold. WDO may be used to generate a reset pulse by connecting it
to the MR input.
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Operation
3.5
STM706T/S/R, STM706P, STM708T/S/R
Power-fail input/output
The power-fail input (PFI) is compared to an internal reference voltage (independent from
the VRST comparator). If PFI is less than the power-fail threshold (VPFI), the power-fail
output (PFO) will go low. This function is intended for use as an undervoltage detector to
signal a failing power supply. Typically PFI is connected through an external voltage divider
(see Figure 9) to either the unregulated DC input (if it is available) or the regulated output of
the VCC regulator. The voltage divider can be set up such that the voltage at PFI falls below
VPFI several milliseconds before the regulated VCC input to the STM70x or the microprocessor drops below the minimum operating voltage.
If the comparator is unused, PFI should be connected to VSS and PFO left unconnected.
PFO may be connected to MR on the STM70x so that a low voltage on PFI will generate
a reset output.
3.6
Ensuring a valid reset output down to VCC = 0 V
When VCC falls below 1 V, the state of the RST output can no longer be guaranteed, and
becomes essentially an open circuit. If a high value pulldown resistor is added to the RST
pin, the output will be held low during this condition. A resistor value of approximately
100 kΩ will be large enough to not load the output under operating conditions, but still
sufficient to pull RST to ground during this low voltage condition (see Figure 10).
Figure 10. Reset output valid to ground circuit
STM70x
RST
R1
AI08844
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STM706T/S/R, STM706P, STM708T/S/R
3.7
Operation
Interfacing to microprocessors with bi-directional reset pins
Microprocessors with bi-directional reset pins can contend with the STM70x reset output.
For example, if the reset output is driven high and the micro wants to pull it low, signal
contention will result. To prevent this from occurring, connect a 4.7kΩ resistor between the
reset output and the micro's reset I/O as in Figure 11.
Figure 11. Interfacing to microprocessors with bi-directional reset I/O
Buffered reset to other
system components
VCC
VCC
STM70x
Microprocessor
4.7 kΩ
RST
GND
RST
GND
AI08845
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Typical operating characteristics
4
STM706T/S/R, STM706P, STM708T/S/R
Typical operating characteristics
Typical values are at TA = 25 °C.
Figure 12. Supply current vs. temperature (no load)
30
25
Supply current (µA)
20
15
VCC = 2.7 V
VCC = 3.0 V
VCC = 3.6 V
VCC = 4.5 V
VCC = 5.5 V
10
5
0
–40
–20
0
20
40
60
80
100
120
Temperature (°C)
AI09141b
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Typical operating characteristics
Figure 13. VPFI threshold vs. temperature
1.270
1.265
V PFI threshold (V)
1.260
1.255
VCC = 2.5 V
VCC = 3.0 V
VCC = 3.3 V
VCC = 3.6 V
1.250
1.245
1.240
1.235
1.230
1.225
–40
–20
0
20
40
Temperature (°C)
60
80
100
120
AI09142b
Figure 14. Reset comparator propagation delay vs. temperature
30
28
Propagation delay (µs)
26
24
22
20
18
16
14
12
10
–40
–20
0
20
40
60
Temperature (°C)
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80
100
120
AI09143b
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Typical operating characteristics
STM706T/S/R, STM706P, STM708T/S/R
Figure 15. Power-up trec vs. temperature
240
235
t rec (ms)
230
VCC = 3.0 V
225
VCC = 4.5 V
VCC = 5.5 V
220
215
210
–40
–20
0
20
40
60
Temperature (°C)
80
100
120
AI09144b
Figure 16. Normalized reset threshold vs. temperature
Normalized reset threshold
1.004
1.002
1.000
0.998
0.996
–40
–20
0
20
40
60
Temperature (°C)
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80
100
120
AI09145b
STM706T/S/R, STM706P, STM708T/S/R
Typical operating characteristics
Figure 17. Watchdog timeout period vs. temperature
1.90
Watchdog timeout period (s)
1.85
1.80
1.75
VCC = 3.0 V
VCC = 4.5 V
VCC = 5.5 V
1.70
1.65
1.60
–40
–20
0
20
40
60
80
100
120
Temperature (˚ C)
AI09146b
Figure 18. PFI to PFO propagation delay vs. temperature
4.0
VCC = 3.0 V
VCC = 3.6 V
PFI to PFO propagation dela
3.0
VCC = 4.5 V
VCC = 5.5 V
2.0
1.0
0.0
–40
–20
0
20
40
60
Temperature (˚C)
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80
100
120
AI09148b
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Typical operating characteristics
STM706T/S/R, STM706P, STM708T/S/R
Figure 19. Output voltage vs. load current (VCC = 5 V; TA = 25 °C)
5.00
V OUT (V)
4.98
4.96
4.94
0
10
20
30
40
50
I OUT (mA)
AI10496
Figure 20. RST output voltage vs. supply voltage
5
5
V RST (V)
VRST
VCC
4
4
3
3
2
2
1
1
0
0
V CC (V)
500 ms / div
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STM706T/S/R, STM706P, STM708T/S/R
Typical operating characteristics
Figure 21. RST output voltage vs. supply voltage
5
5
V RST
VCC
V RST (V)
4
4
3
3
V CC (V)
2
2
1
1
0
0
500 ms / div
AI09150b
Figure 22. Power-fail comparator response time (assertion)
9
9 GLY
3)2
9
9
3),
P9 GLY
9
QV GLY
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Typical operating characteristics
STM706T/S/R, STM706P, STM708T/S/R
Figure 23. Power-fail comparator response time (de-assertion)
9
9 GLY
3)2
9
9
3),
P9 GLY
9
QV GLY
Figure 24. Maximum transient duration vs. reset threshold overdrive
6000
Transient duration (µs)
5000
4000
Reset occurs
above the curve
3000
2000
1000
0
0.001
0.01
0.1
Reset comparator overdrive, V RST – V CC (V)
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10
AI09156b
STM706T/S/R, STM706P, STM708T/S/R
5
Maximum ratings
Maximum ratings
Stressing the device above the rating listed in the Table 4: Absolute maximum ratings may
cause permanent damage to the device. These are stress ratings only and operation of the
device at these or any other conditions above those indicated in Table 5: Operating and AC
measurement conditions of this specification is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability.
Table 4. Absolute maximum ratings
Symbol
TSTG
TSLD(1)
VIO(2)
Parameter
Storage temperature (VCC off)
Lead solder temperature for 10 seconds
Input or output voltage
Value
Unit
–55 to 150
°C
260
°C
–0.3 to VCC +0.3
V
VCC
Supply voltage
–0.3 to 7.0
V
IO
Output current
20
mA
PD
Power dissipation
320
mW
1. Reflow at peak temperature of 260 °C. The time above 255 °C must not exceed 30 seconds.
2. Negative undershoot of –1.5 V for up to 10 ns or positive overshoot of VCC + 1.5 V for up to 10 ns is
allowable on the WDI and MR input pins.
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DC and AC parameters
6
STM706T/S/R, STM706P, STM708T/S/R
DC and AC parameters
This section summarizes the operating measurement conditions, and the DC and AC
characteristics of the device. The parameters in Table 6: DC and AC characteristics are
derived from tests performed under the measurement conditions summarized in Table 5:
Operating and AC measurement conditions. Designers should check that the operating
conditions in their circuit match the operating conditions when relying on the quoted
parameters.
Table 5. Operating and AC measurement conditions
Parameter
STM70x
Unit
VCC supply voltage
1.0 to 5.5
V
Ambient operating temperature (TA)
–40 to 85
°C
≤5
ns
Input pulse voltages
0.2 to 0.8 VCC
V
Input and output timing ref. voltages
0.3 to 0.7 VCC
V
Input rise and fall times
Figure 25. AC testing input/output waveforms
0.8 V CC
0.7 V CC
0.3 V CC
0.2 V CC
AI02568
Figure 26. Power-fail comparator waveform
VCC
VRST
trec
PFO
RST
AI08860a
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DC and AC parameters
Figure 27. MR timing waveform
MR
RST
(1)
tMLRL
tMLMH
trec
AI07837a
1. RST for STM706P and STM708T/S/R.
Figure 28. Watchdog timing (STM706T/S/R and STM706P)
VCC
RST
trec
tWD
WDI
WDO
AI08833
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DC and AC parameters
STM706T/S/R, STM706P, STM708T/S/R
Table 6. DC and AC characteristics
Symbol
Description
VCC
Operating voltage
ICC
VCC supply current
ILI
Typ.
1.2(2)
Max.
Unit
5.5
V
VCC < 3.6 V
35
50
µA
VCC < 5.5 V
40
60
µA
0 V < VIN < VCC
–1
+1
µA
Input leakage current
(WDI) with watchdog
disable feature (“D”
version)
0 V < VIN < VCC
-110
110
µA
Input leakage current
(PFI)
0 V < VIN < VCC
–25
2
+25
nA
VRST (max.) < VCC < 3.6 V
25
80
250
µA
4.5 V < VCC < 5.5 V
75
125
300
µA
4.5 V < VCC < 5.5 V
2.0
V
VRST (max.) < VCC < 3.6 V
0.7 VCC
V
VRST (max.) < VCC < 5.5 V
0.7 VCC
V
VIH
Input high voltage (MR)
VIH
Input high voltage (WDI)
VIL
Input low voltage (MR)
VIL
Input low voltage (WDI)
VOL
Output low voltage (PFO,
RST, RST, WDO)
VOH
Min.
Input leakage current
(WDI)
Input leakage current
(MR)
VOL
Test condition(1)
Output low voltage (RST)
4.5 V < VCC < 5.5 V
0.8
V
VRST (max.) < VCC < 3.6 V
0.6
V
VRST (max.) < VCC < 5.5 V
0.3 VCC
V
VCC = VRST (max.),
ISINK = 3.2 mA
0.3
V
ISINK = 50 µA, VCC = 1.0 V,
TA = 0 °C to 85 °C
0.3
V
ISINK = 100 µA,
VCC = 1.2 V
0.3
V
Output high voltage (RST,
RST, WDO)
ISOURCE = 1 mA,
VCC = VRST (max.)
2.4
V
Output high voltage
(PFO)
ISOURCE = 75 µA,
VCC = VRST (max.)
0.8 VCC
V
PFI falling
(STM70xP/R, VCC = 3.0 V;
STM70xS/T, VCC = 3.3 V)
1.20
Power-fail comparator
VPFI
PFI input threshold
tPFD
PFI to PFO propagation
delay
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2
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1.30
V
µs
STM706T/S/R, STM706P, STM708T/S/R
DC and AC parameters
Table 6. DC and AC characteristics (continued)
Symbol
Description
Test condition(1)
Min.
Typ.
Max.
Unit
STM706P/70xR
2.55
2.63
2.70
V
STM70xS
2.85
2.93
3.00
V
STM70xT
3.00
3.08
3.15
V
Reset thresholds
VRST
Reset threshold(3)
Reset threshold
hysteresis
trec
20
RST pulse width
mV
Blank (see Table 9)
140
200
280
A(4) (see Table 9)
160
200
280
VRST (max.) < VCC < 3.6 V
500
ns
4.5 V < VCC < 5.5 V
150
ns
ms
Push-button reset input
tMLMH
(or tMR)
MR pulse width
tMLRL
MR to RST output delay
(or tMRD)
VRST (max.) < VCC < 3.6 V
750
ns
4.5 V < VCC < 5.5 V
250
ns
2.24
s
Watchdog timer (STM706T/S/R and STM706P)
tWD
Watchdog timeout period
WDI pulse width
STM706P/70xR,
VCC = 3.0 V
1.12
1.60
STM70xS/70XT,
VCC = 3.3 V
4.5 V < VCC < 5.5 V
50
ns
VRST (max.) < VCC < 3.6 V
100
ns
1. Valid for ambient operating temperature: TA = –40 to 85 °C; VCC = VRST (max.) to 5.5 V (except where noted).
2. VCC (min) = 1.0 V for TA = 0 °C to +85 °C.
3. For VCC falling.
4. STM706P/STM70xR device, VCC = 3 V; STM706xS/STM70xT device, VCC = 3.3 V.
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Package information
7
STM706T/S/R, STM706P, STM708T/S/R
Package information
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK® is an ST trademark.
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7.1
Package information
SO8 package information
Figure 29. SO8 - 8-lead plastic small outline, 150 mils body width, package outline
A2
A
C
B
ddd
e
D
8
E
H
1
A1
L
SO-A
Note:
Drawing is not to scale.
Table 7. SO8 - 8-lead plastic small outline, 150 mils body width, mechanical data
Dimensions
Symbol
mm
inches
Typ.
Min.
Max.
Typ.
Min.
Max.
A
—
1.35
1.75
—
0.053
0.069
A1
—
0.10
0.25
—
0.004
0.010
B
—
0.33
0.51
—
0.013
0.020
C
—
0.19
0.25
—
0.007
0.010
D
—
4.80
5.00
—
0.189
0.197
ddd
—
—
0.10
—
—
0.004
E
—
3.80
4.00
—
0.150
0.157
e
1.27
—
—
0.050
—
—
H
—
5.80
6.20
—
0.228
0.244
h
—
0.25
0.50
—
0.010
0.020
L
—
0.40
0.90
—
0.016
0.035
α
—
0°
8°
—
0°
8°
N
8
8
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Package information
7.2
STM706T/S/R, STM706P, STM708T/S/R
TSSOP8 3x3 (DS) package information
Figure 30. TSSOP8 - 8-lead, thin shrink small outline, 3 x 3 mm body size,
package outline
D
8
5
c
E1
1
E
4
A1
A
L
A2
L1
CP
b
e
TSSOP8BM
Note:
Drawing is not to scale.
Table 8. TSSOP8 - 8-lead, thin shrink small outline, 3 x 3 mm body size,
mechanical data
Dimensions
Symbol
28/32
mm
inches
Typ.
Min.
Max.
Typ.
Min.
Max.
A
—
—
1.10
—
—
0.043
A1
—
0.05
0.15
—
0.002
0.006
A2
0.85
0.75
0.95
0.034
0.030
0.037
b
—
0.25
0.40
—
0.010
0.016
c
—
0.13
0.23
—
0.005
0.009
CP
—
—
0.10
—
—
0.004
D
3.00
2.90
3.10
0.118
0.114
0.122
e
0.65
—
—
0.026
—
—
E
4.90
4.65
5.15
0.193
0.183
0.203
E1
3.00
2.90
3.10
0.118
0.114
0.122
L
0.55
0.40
0.70
0.022
0.016
0.030
L1
0.95
—
—
0.037
—
—
α
—
0°
6°
—
0°
6°
N
8
8
DocID10518 Rev 13
STM706T/S/R, STM706P, STM708T/S/R
8
Part numbering
Part numbering
Table 9. Ordering information scheme
Example:
STM706
T
D
M
6
F
Device type
STM706
STM708
Reset threshold voltage
T: 3.00 V ≤ VRST ≤ 3.15 V
S: 2.88 V ≤ VRST ≤ 3.00 V
R: STM706P: 2.59 V ≤ VRST ≤ 2.70 V
Watchdog disable
Blank = not activated
D = activated
RST pulse width
Blank = 140 to 280 ms
A(1) = 160 to 280 ms
Package
M = SO8
DS(2) = TSSOP8
Temperature range
6 = –40 to 85 °C
Shipping method
F = ECOPACK® packages, tape and reel
1. Available in SO8 (M) package only
2. Contact local ST sales office for availability
For other options, or for more information on any aspect of this device, please contact the ST sales office
nearest you.
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31
Part numbering
STM706T/S/R, STM706P, STM708T/S/R
Table 10. Marking description
30/32
Part number
Reset threshold
STM706P
2.63 V
STM706T
3.08 V
STM706S
2.93 V
STM706R
2.63 V
STM706RD
2.63 V
STM708T
3.08 V
STM708S
2.93 V
STM708R
2.63 V
DocID10518 Rev 13
Package
SO8
TSSOP8
SO8
TSSOP8
SO8
TSSOP8
SO8
TSSOP8
SO8
TSSOP8
SO8
TSSOP8
SO8
TSSOP8
SO8
TSSOP8
Topside marking
706P
706T
706S
706R
706RD
708T
708S
708R
STM706T/S/R, STM706P, STM708T/S/R
9
Revision history
Revision history
Table 11. Document revision history
Date
Revision
Oct-2003
1
Initial release.
12-Dec-2003
2
Reformatted; update characteristics (Figure 2, 3, 8 to 10, 27 to 29;
Table 6 to 9).
16-Jan-2004
2.1
Add Typical operating characteristics (Figure 13, to 19, 21, to 25).
09-Apr-2004
3
Reformatted; update characteristics (Figure 15, 19, 21, 22, 25; Table 8).
25-May-2004
4
Update characteristics (Table 3, Table 6).
02-Jul-2004
5
Datasheet promoted; waveform corrected (Table 27).
21-Sep-2004
6
Clarify root part numbers; (Figure 2, to 10, 29; Table 1, 3, 6, 9).
25-Feb-2005
7
Update typical characteristics (Figure 13 to 25).
02-Nov-2009
8
Updated Table 1, Table 3, Table 4, Table 6, Table 9, Section 2.3,
Section 2.7, text in Section 7; reformatted document.
30-Apr-2010
9
Updated Table 4, corrected typo in Table 2, Section 2.3, Section 3,
Section 5 and Section 6, Figure 17, Table 7 and Table 8.
06-Aug-2010
10
Updated Features, Section 4: Typical operating characteristics; Table 9.
06-Sep-2011
11
Updated Section 2.7, Section 5 and Disclaimer, minor typo
modifications throughout the document.
21-Aug-2012
12
Added Applications, updated Section 2.2 and Section 2.3, added note
to Section 3.3, added cross-references in Section 5 and Section 6,
minor text corrections throughout document.
13
Updated layout of cover page and Section 7: Package information.
Added information about the watchdog disable function to Section 2.2:
WDI, Table 6, Table 9, and Table 10.
Table 9: removed the “E” option (tubes) from shipping method
15-Dec-2015
Changes
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STM706T/S/R, STM706P, STM708T/S/R
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Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or
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