S52xxM
Electrical Characteristic Curves (Cont.)
Fig. 7.
Fig. 8
Shutdown (Dis/Enable) Operation
The S52xxM output can be turned off by applying 0.4V or less to the device’s Dis/Enable
pin (pin3). In shutdown mode, the S52xxM draws less than 1uA quiescent current. The
output of the S52xxM is enabled by applying 1.5V to 13V at the Dis/Enable pin. In
applications were the S52xxM output will always remain enabled, the Dis/Enable pin may
be connected to Vin(pin1). The S52xxM’s shutdown circuitry includes hysteresis, as such
the device will operate properly even if a slow moving signal is applied to the Dis/Enable
pin. The device’s shutdown pin includes a 2MΩ internal pull down resistor connected to
ground.
Short Circuit Protection
The S52xxM output can withstand momentary short circuit to ground. Moreover, the
regulator can deliver very high output peak current due to its 1A instantaneous short circuit
current capability.
Noise Bypass Capacitor
In low noise applications, the self noise of the S52xxM can be decreased further by
connecting a capacitor from the noise bypass pin (pin4) to ground (pin2). The noise bypass
pin is a high impedance node as such care should be taken in printed circuit board layout to
avoid noise pick-up from external sources. Moreover, the noise bypass capacitor should
have low leakage. Noise bypass capacitors with a value as low as 470pF may be used.
However, for optimum performance, use a 0.01uF or larger, ceramic chip capacitor. Note
that the turn on and turn off response of the S52xxM is inversely proportional to the value
of the noise bypass capacitor. For fast turn on and turn off, use a small value noise Bypass
capacitor. In applications were exceptionally low output noise is not required, consider
omitting the noise Bypass capacitor altogether.
KSI-2012-006
5
AUK [ AUK CORP ]
