PM6644 Datasheet, PDF (1/35 Pages) STMicroelectronics – 350 mA adjustable step-down regulator

PM6644
350 mA adjustable step-down regulator
Datasheet − production data
Features
■ 4.5 V to 25 V input voltage range
■ Output voltage V_OUT: fixed 3.47 V or adjustable
0.9 V to 8 V
■ 350 mA valley current limit
■ Constant-on-time control
■ Programmable switching frequency
■ Pulse skipping mode (skip mode) at light loads
■ Independent EN signals
■ Latched OVP and UVP
DFN10
switching regulator can be programmed to
regulate a fixed value of 3.47 V or it can deliver an
adjustable voltage, depending on the FB pin set-
up.
Applications
■ Networking power supply
■ Portable applications
■ Microcontroller supply
■ Industrial supply
Description
The PM6644 is a 350 mA valley current limit step-
down regulator capable of delivering an
adjustable output voltage in the range between
0.9 V and 8 V. A fixed value of output voltage is
also available (3.47 V), saving the external
resistor divider. It is housed in a small DFN10 3x3
package. The switching regulator is based on
COT (constant-on-time) architecture, that assures
fast load transient response; the embedded
voltage feed-forward provides nearly constant
switching frequency operation. The pulse skipping
technique increases efficiency at very light load.
The switching frequency can be adjusted from
200 kHz to 600 kHz through a simple resistor. The
Table 1. Device summary
Part number
Package
PM6644
PM6644TR
DFN10
DFN10
Packing
Tube
Tape and reel
June 2012
This is information on a product in full production.
Doc ID 023203 Rev 1
1/35
www.st.com
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