RHFL4913 STMICROELECTRONICS [STMicroelectronics], RHFL4913 Datasheet - Page 5

• Manufacturer Part Number: RHFL4913
• Description: RAD-HARD POSITIVE FIXED VOLTAGE REGULATORS
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Figure 2: Application Diagram For Remote Sensins Operation
DEVICE DESCRIPTION
The RHFL4913 Fixed Voltage contains a PNP type power element controlled by a signal resulting from
amplified comparison between the internal temperature compensated Band-Gap cell and the fraction of
the desired Output Voltage value. This fractional value is obtained from an internal-to-die resistor divider
bridge set by STMicroelectronics. The device is protected by several functional blocks.
Low pin count Package limitations
Some functions (INHIBIT, OCM, SENSE) are not available due to lack of pins. Corresponding die pads
are by default connected inside silicon.
SENSE pin
The Load voltage is applied by a Kelvin line connected to SENSE pin: Voltage feed-back comes from the
internal divider resistor bridge. Therefore possible output voltages are set by manufacturer mask metal
options. SENSE pin is not available in 3pin packages.
INHIBIT ON-OFF Control
By setting INHIBIT pin TTL-High, the Device switches off the Output Current and Voltage. The Device is
ON when INHIBIT pin is set Low. Since INHIBIT pin is internally pulled down, it can be left floating in case
Inhibit function is not utilized. INHIBIT pin is not available in 3pin packages.
Overtemperature protection
A temperature detector internally monitors the power element junction temperature. The Device goes
OFF at approx. 175°C, returning to ON mode when back to approx. 40°C. It is worth noting that when the
internal temperature detector reaches 175°C, the active power element can be at 225°C: Device reliability
cannot be granted in case of extensive operation under these conditions.
Overcurrent protection
I
can be reduced by an external resistor connected between I
of 10k
regulation, it is necessary to set I
I
flag is risen. When no current limitation adjustment is required, I
pin packages).
OCM pin
Goes Low when current limiter starts to be active, otherwise V
OCM pin is internally pulled-up by a 5 k resistor. Not available in 3pin packages.
SC
O
reaches I
pin. An internal non-fold back Short-Circuit limitation is set with I
to 200k . This adjustment feature is not available in 3pin packages. To keep excellent V
SHORT
– 300mA, the current limiter overrules Regulation and V
SHORT
1.6 times greater than the maximum desired application I
SC
OCM
pin and V
SC
= V
pin must be left unbiased (as it is in 3
SHORT
I
. It is bufferized and can sink 10mA.
RHFL4913 FIXED VERSION
I
pin, with a typical value range
O
> 3.8A (V
starts to drop and the OCM
O
is 0V). This value
O
. When
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O