28Vin up to 6A synchronous 4-switch buck-boost converter

ELM631FA is a wide input range fully integrated 4-switch synchronous buck-boost converter capable of regulating the output voltage at, above, or below the input voltage. The device employs the patented peak current mode with constant off-time control scheme that significantly simplifies control loop design and offers seamless transition between Buck, Buck-Boost and Boost mode operations. Proprietary inductor DCR current sensing eliminates the need for external current sense resistor and improves system power efficiency. With external compensation, ELM631FA can be optimized to operate with a wide range of input and output voltage at all current levels. ELM631FA comes with internal soft-start, programmable inductor peak current limit, input under-voltage and over-voltage lockout, hiccup mode for short circuit or overload protection and thermal shutdown. The high integration level of ELM631FA offers great ease of use and minimizes the external components as well as board space. ELM631FA is available with a small footprint 5mmx5mm 28-lead QFN package.

Inductor DCR current sensing
Programmable input switch current limit
Accurate EN threshold voltage
Output voltage power good indicator
Cycle-by-Cycle peak current limit
Short circuit protection with hiccup mode
Input voltage range3.1V to 28.0V
Output voltage range1.0V to 28.0V
Switch transistor17mΩ/20A
Nch MOS×4
Output current5A (Input voltage 4.5V to 20V)
6A (Input voltage 20V or more)
Switching frequency600kHz
Thermal shutdown155°C
Show datasheet
USB type C hub
5V, 9V, 12V, 20V and 24V VDC bus power
USB-PD and thunderbolt ports for PCs
Power banks and electronic cigarette
Tablet computer accessories
Industrial battery powered systems

Absolute Maximum Ratings

VIN-AGND Supply voltageVin-0.3 to +30.0V
VOUT-AGND Supply voltageVout-0.3 to +30.0V
EN-AGND Supply voltageVen-0.3 to +30.0V
CSP-AGND Supply voltageVcsp-0.3 to +30.0V
CSN-AGND Supply voltageVcsn-0.3 to +30.0V
CSP-CSN Supply voltageVcsp-csn-0.3 to +0.3V
SW1-AGND Supply voltageVsw1-agnd-0.3 to Vin+0.6V
Dynamic SW1 in 50ns durationVsw1-3 to Vin+3V
SW2-AGND Supply voltageVsw2-agnd-0.3 to Vout+0.6V
Dynamic SW2 in 50ns durationVsw23 to Vout+3V
BST1-SW1 Supply voltageVbst1-sw1-0.3 to +6.0V
BST2-SW2 Supply voltageVbst2-sw2-0.3 to +6.0V
PGND-AGND Supply voltageVpgnd-agnd-0.3 to +0.3V
The other pins to AGNDVother-0.3 to +6.0V
Lead temperatureTL+260°C
Junction temperature rangeTj-40 to +150°C
Storage temperature rangeTstg-55 to +150°C
Thermal resistanceθja35.6°C/W
Thermal resistanceθjc12.0°C/W
Power dissipationPd3.5W

Block diagram