GS-R51212S STMicroelectronics, GS-R51212S Datasheet - Page 5

• Manufacturer Part Number: GS-R51212S
• Description: Switching Converters, Regulators & Controllers +5.1/+12/-12V Stp-Dn
• Manufacturer: STMicroelectronics
• Type: Step Downr

Specifications of GS-R51212S

• Input Voltage: 15 to 40V
• Screening Level: Commercial
• Operating Temperature Min Deg. C: 0C
• Operating Temperature Max Deg. C: 85C
• Product Depth (mm): 50.8mm
• Mounting Style: Screw
• Pin Count: 11
• Number Of Outputs: 3
• Package / Case: Module
• Lead Free Status / RoHS Status: Supplier Unconfirmed

USER NOTES
Input Voltage
The recommended operating maximum DC input
voltage is 40V inclusive of the ripple voltage. The
use of an external low ESR, high ripple current
capacitor located as close the module as possible
is recommended; suggested value is 100 F/50V.
Soft-start
To avoid heavy inrush current the output voltage
rise time is typically 10ms in any condition of load.
Power Fail-Reset Circuit
The module include a voltage sensing circuit that
may be used to generate a power-on/power-off
reset signal for a microprocessor system.
The circuit sense the input supply voltage and the
output generated voltage Vo1 (+5V) and will gener-
ate the required reset signal only when both the
sensed voltages have reached the required value
for correct system operation.
When both the supply voltage and the regulated
voltage are in the correct range the output Reset
signal is generated after a delay time t
typical.
A latch assures that if a spike is present on the
sensed voltage the delay time circuit discharges
completely before initialization of a new reset cycle.
Figure 1 - Reset and Power Fail waveforms.
DR
of 100ms
Reset output has internal pull-up resistor of
10kOhm connected to Vo +5V pin.
Maximum sink output current is 20mA at
V
Fig. 1 and fig. 2 show reset waveforms.
Power Fail Programmable Input
This pin is internally connected via a divider to the
+Vin pin for Power Fail function.
The factory setting is for a value of 11V with 1V
hysteresis.
It is possible to program a different value of Power
Fail threshold by connecting a resistor (Rpf) be-
tween pin 3 (Power Fail Input) and pin 1 (GND
Input). The value of Rpf must be calculated accord-
ing to the following formula:
where Vpf is the desired value of Power Fail thresh-
old voltage.
Exampe: Vpf = 24V (must not be lower than 12V):
RESET(sat)
R
R
pf
pf
= 200mV.
24
V
pf
GS-R51212S/GS-R51515S
34
34
5.1
5.1
5.1
5.1
0.191
0.191
14k
k
5/8