DESCRIPTION
The L4974Aisa step down monolithic power switch ing regulator delivering 3.5A at a voltage variable from 5.1 to 40V.
Realized with BCD mixed technology, the device uses a DMOS output transistor to obtain very high efficiencyand very fastswitching times. Features of the L4974A include reset and power fail for micro processors, feed forward line regulation, soft start, limiting current and thermal protection. The device is mountedin a Powerdip16 + 2 + 2 plastic package and requires few external components. Efficient operation at switching frequencies up to 200KHz allows reductionin the size and cost of externalfilter component.

. 3.5A OUTPUT CURRENT
. 5.1V TO 40V OUTPUT VOLTAGE RANGE
. 0 TO 90% DUTY CYCLE RANGE
. INTERNAL FEED-FORWARD LINE REG.
. INTERNAL CURRENT LIMITING
. PRECISE 5.1V ± 2% ON CHIP REFERENCE
. RESET AND POWER FAIL FUNCTIONS
. INPUT/OUTPUT SYNC PIN
. UNDER VOLTAGE LOCK OUT WITH HYSTERETIC TURN-ON
. PWM LATCH FOR SINGLE PULSE PER PERIOD
. VERY HIGH EFFICIENCY
. SWITCHING FREQUENCY UP TO 200KHz
. THERMAL SHUTDOWN
. CONTINUOUS MODE OPERATION