Device description

RHFL7913A

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Device description

The RHFL7913A adjustable contains a NPN-type power element controlled by signal

resulting from amplified comparison between internal temperature compensated band-gap

cell and the fraction of the desired output voltage value, generated by an external resistor

divider bridge. The NPN structure allows access to lower drop out levels because its base

current can be routed to ground pin and not to output. To control and monitor the device

from / to the external logic world – usually operating in positive voltage area – a dedicated

logic interface block (INHIBIT and OCM functions) has been implemented with +3 V to +5 V

supplied line V(+). In case V(+) = 0 V, inhibit and OCM functions are not available: In this

condition, INHIBIT function is ON and OCM pin is “no care”. The device is internally

protected by several blocks.

5.1

ADJ pin

The load voltage feed back comes from an external divider resistor bridge middle point to

ADJ pin established between load terminals.

5.2

Inhibit ON-OFF control

When INHIBIT pin is TTL-high (positive), the device switches off current and voltage output.

The device is ON when INHIBIT pin is set TTL-low.

5.3

Overtemperature protection

A temperature detector internally monitors power element junction temperature. The device

goes OFF circa 165 °-175 °C are reached, and returns ON when circa 100 °C. When

internal temperature detector reaches 170 °C, the active power element can be at 225 °C:

Device reliability cannot be granted during extensive operation duration with these

conditions.

5.4

Overcurrent protection

pins, with a typical value range of 10 k

unbiased (as it is in 3 pin packages).

5.5

OCM pin

and can sink 10 mA. OCM pin is internally pulled-up by a 50 k

Ω resistor. Can left open when

V (+) = 0.