The RT6206BH is a synchronous step-down DC/DC converter with Advanced Constant On-Time (ACOT™) mode control. This document explains the function and use of the RT6206BH evaluation board (EVB), and provides information to enable operation, modification of the evaluation board and circuit to suit individual requirements.
The RT6206BH is a synchronous step-down DC/DC converter with Advanced Constant On-Time (ACOT™) mode control. It achieves high power density to deliver up to 5.5A output current from a 4.5V to 18V input supply. The proprietary ACOT™ mode offers an optimal transient response over a wide range of loads and all kinds of ceramic capacitors, which allows the device to adopt very low ESR output capacitor for ensuring performance stabilization. In addition, RT6206BH keeps an excellent constant switching frequency under line and load variation and the integrated synchronous power switches with the ACOT™ mode operation provides high efficiency in whole output current load range. Cycle-by-cycle current limit provides an accurate protection by a valley detection of low side MOSFET and external soft-start setting eliminates input current surge during startup. Protection functions include thermal shutdown for RT6206BH.
Key Features
Evaluation Board Number : PCB066_V1
Input Voltage Range
4.5V to 18V
Max Output Current
5.5A
Default Output Voltage
1.05V
Default Marking & Package Type
RT6206BHGQW, WDFN-10L 3x3
Operation Frequency
650kHz
Please carefully inspect the EVB IC and external components, comparing them to the following Bill of Materials, to ensure that all components are installed and undamaged. If any components are missing or damaged during transportation, please contact the distributor or send e-mail to evb_service@richtek.com.
The EVB is provided with the test points and pin names listed in the table below.
Test point/
Pin name
Signal
Comment (expected waveforms or voltage levels on test points)
VIN
Input voltage
Power input.
EN
Enable test point
Externally pulled high to enable and pulled low to disable this chip. It is internally pulled up to high when the pin is floating.
GND
Ground
The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation.
VREG5
Internal Regulator Output
Internal Regulator Output. Connect a 1μF capacitor to GND to stabilize output voltage.
SS
Soft-Start Control.
Connect an external capacitor between this pin and GND to set the soft-start time.
PG
Power good test point
Output of power good indicator.
BOOT
Bootstrap supply test point
Bootstrap supply for high-side gate driver. Connect a capacitor between the BOOT and SW pins.
SW
Switch node test point
Connect this pin to an external L-C filter.
1. Apply a 12V nominal input power supply (4.5 < VIN < 18V) to the VIN and GND terminals.
2. Set the jumper at JP1to connect terminals 2 and 3, connecting EN to enable operation.
3. Verify the output voltage (approximately 1.05V) between VOUT and GND.
4. Connect an external load up to 5.5A to the VOUT and GND terminals and verify the output voltage and current.
Output Voltage Setting
Set the output voltage with the resistive divider (R2, R3) between VOUT and GND with the midpoint connected to FB. The output is set by the following formula :
Reference
Qty
Part Number
Description
Package
Manufacture
U1
1
RT6206BHGQW
DC/DC Converter
WDFN-10L 3x3
RICHTEK
C1, C3
2
GRM31CR71E106KA12L
10µF/25V/X7R
C-1206
MURATA
C4, C10, C7
3
C1608X7R1H104KT000N
0.1µF/50V/X7R
C-0603
TDK
C8, C9
GRM31CR61A226KE19L
22µF/10V/X5R
C6
0603B332K500
3.3nF/50V/X7R
WALSIN
C5
C2012X7R1E105KT
1µF/25V/X7R
C-0805
C2
NC
L1
NR8040T1R4N
1.4µH/7A
8 x 8 x 4 mm
TAIYO YUDEN
R2
8.25k
R-0603
R3
22.1k
R1, R4
100k
Top View (1st layer)
PCB Layout—Inner Side (2nd Layer)
PCB Layout—Inner Side (3rd Layer)
Bottom View (4th Layer)
