L6985F Datasheet, PDF (1/65 Pages) STMicroelectronics – Internal current limiting

L6985F
38 V, 500 mA synchronous step-down switching regulator
with 30 µA quiescent current
Datasheet - production data
HTSSOP16 (R_TH = 40 °C/W)
Features
 0.5 A DC output current
 4 V to 38 V operating input voltage
 Low consumption mode or low noise mode
 30 µA I_Q at light-load (LCM V_OUT = 3.3 V)
 8 µA _IQ-SHTDWN
 Output voltage adjustable from 0.85 V to V_IN
 Adjustable f_SW (250 kHz - 2 MHz)
 Embedded output voltage supervisor
 Synchronization
 Adjustable soft-start time
 Internal current limiting
 Overvoltage protection
 Output voltage sequencing
 Peak current mode architecture
 R_{DSON HS} = 360 m, R_{DSON LS} = 150 m
 Thermal shutdown
Description
The L6985F is a step-down monolithic switching
regulator able to deliver up to 0.5 A DC. The
output voltage adjustability ranges from 0.85V to
VIN. Thanks to the P-channel MOSFET high-side
power element, the device features 100% of the
duty cycle operation. The wide input voltage
range meets the specification for the 5 V, 12 V
and 24 V power supplies. The “Low Consumption
Mode” (LCM) is designed for applications active
during the idle mode, so it maximizes the
efficiency at the light-load with the controlled
output voltage ripple. The “Low Noise Mode”
(LNM) makes the switching frequency constant
overload current range, meeting the low noise
application specification. The output voltage
supervisor manages the reset phase for any
digital load (µC, FPGA). The RST open collector
output can also implement output voltage
sequencing during the power-up phase. The
synchronous rectification, designed for high
efficiency at the medium - heavy load, and the
high switching frequency capability make the size
of the application compact. Pulse-by-pulse
current sensing on both power elements
implements effective constant current protection.
Applications
 Designed for 12 V and 24 V buses
 Programmable logic controllers (PLCs)
 Decentralized intelligent nodes
 Sensors and low noise applications (LNM)
February 2016
This is information on a product in full production.
DocID027836 Rev 2
1/65
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