MK9218 Synchronous Buck DC/DC Controller

Table of Contents

The MK9218 operates over a wide input voltage range from 6V to 100V. With appropriate high-side and low-side MOSFET and Inductance, the MK9218 delivers up to 30A output current. The MK9218 adopts a voltage mode control architecture to achieve excellent accurate voltage output.

The switching frequency is adjustable up to 1 MHz, which also can be synchronized to an external clock source to eliminate beat frequencies in noise-sensitive applications. MK9218 support Forced-PWM (FPWM) and Diode Emulation Mode; FPWM operation eliminates switching frequency variation to minimize EMI, while user selectable diode emulation lowers current consumption at light-load condition.

MK9218 is offered with wide duty cycle from 1% to 98% under appropriate switching frequency, so input and output voltage can easy to be choose. The MK9218 provides a power good (PG) flag pin to indicate output voltage.

Mk9218 Synchronous Buck Dcdc Controller Load Test

Features MK9218 IC

Wide Input Voltage 6V-100V
Adjustable output from 0.8V to 60V
40ns ton(min) for low duty ratio
190ns toff(min) for high duty ratio
Precision ±1% Feedback Reference
Adjustable FSW from 100kHz to 1MHz
Configuration diode emulation or FPWM
2.5A source and 3.5A sink driver ability
Prebias start-up
SYNCI and SYNCO capability
Open-Drain Power Good Indicator
Adjustable output voltage soft start
Input UVLO with hysteresis
VCC and BOOT UVLO protection
OC, OT Protection with Hiccup Mode
QFN20L 4.5mm x 3.5mm Package with
Thermal PAD

Replace LM25145/LM5145/LM5146

Schematic MK9218 Synchronous Buck DC/DC Controller

About this circuit

Input voltage: designed for 13-25V
Output voltage constant at 12V
Maximum output current of 10A
Model MK9218CQB
Driving current above 2A.

BOM MK9218 Synchronous Buck DC/DC Controller

Parts	Value	Description	Quantity
Resistors
RB	1.27K	R0402 – SMD Resistor	1
RCO	1.91K	R0402 – SMD Resistor	1
REB,RPG,RUP1	20K	R0402 – SMD Resistor	3
RET1	33.2K	R0402 – SMD Resistor	1
RF	1.37K	R0402 – SMD Resistor	1
RFS	39.2K	R0402 – SMD Resistor	1
RIL	715	R0402 – SMD Resistor	1
RT	18kΩ	R0402 – SMD Resistor	1
RVI	2	R0402 – SMD Resistor	1
Capacitors
CBS	100nF	C0603- – SMD Capacitor	1
CI1	100uF/35V	Polymer Aluminum Capacitor	1
CI2,CI3,CI4,CI5,CO2,CO3,CO4,CO5	22uF/16V	C1210 – SMD Capacitor	8
CO1	470uF/25V	Polymer Aluminum Capacitor	1
CVC	2.2uF	C0603 – SMD Capacitor	1
CCO1	8.2nF	C0402 – SMD Capacitor	1
CCO2	680pF	C0402 – SMD Capacitor	1
CF	560pF	C0402 – SMD Capacitor	1
CSS	47nF	C0402 – SMD Capacitor	1
CVI	100nF	C0402 – SMD Capacitor	1
Semiconductors
QB	CSD18540Q5B	60V 100A N-Channel VSON-8(5×6) MOSFET	1
QT	NTMFS5C670NLT1G	60V 35A N-Channel DFN-5(5×6) MOSFET	1
LPG	VLMG1500-GS08	20mA Green 0402 LED	1
U1	MK9218CQB	VQFN-20 100V Synchronous Buck DC/DC Controller	1
Miscellaneous
DC1	DC-042C-W-2.0	6.3mm DC Power Connector	1
SW1	SK-3296S-01-L3	Horizontal attachment Single Pole Double Throw (SPDT) SMD Slide Switch	1
XT-OUT	XT30PW-M	Socket XT30 male 2 pin 15A 500V	1
L1	10uH	10uH 15A SMD-3P 15.5×15.5mm Power Inductor	1