RT6243A/B
Ordering Information
RT6243A/B
Package Type
QVF : VQFN-18L 3.5x3.5 (FC) (V-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Enable Pin
A : Internal pull high
B : Internal pull low
Note :
Richtek products are :
RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
Suitable for use in SnPb or Pb-free soldering processes.
Functional Pin Description
Pin No.
Pin Name
Pin Function
Bootstrap, supply for high-side gate driver. Connect a 0.1F ceramic capacitor
between BOOT and SW pins.
1
BOOT
Input voltage. Support 4.5V to 17V input voltage. Suggest to place equal-value
input capacitors on each side of the IC and as close to the VIN and PGND pins as
possible.
2, 11
VIN
System GND. The power GND of the controller circuit and the regulated output
voltage. Use wide PCB traces to make the connections. AGND and PGND are
connected with a short trace and at only one point to reduce circulating currents.
3, 4, 5, 8, 9, 10 PGND
6, 7
12
SW
Switch node. Connect to power inductor.
Analog GND. AGND and PGND are connected with a short trace and at only one
point to reduce circulating currents.
AGND
Feedback input. The pin is used to set the output voltage of the converter via a
resistor divider. Suggest to place the FB resistor divider as close to FB pin and
AGND as possible.
13
14
15
FB
SS
EN
Soft-start time control pin. Connect a capacitor between the SS pin and AGND to
set the soft-start time. The default internal start-up time is 1ms without external
capacitor.
IC enable.
RT6243A : Internal pull high.
RT6243B : Internal pull low.
Open-drain, power-good indication output. It is pulled low if the feed-back voltage
is out of PGOOD threshold, IC shutdown from OTP and EN goes low, and before
the soft start is finished. A pull-up resistor of 10k to 100k is recommended if this
function is used.
16
PGOOD
4.7V internal LDO output. Connect a 4.7F capacitor as close to the VCC pin as
possible. It does not recommend to connect VCC to supply others rails.
17
18
VCC
Switching frequency, current limit selection and light load operation mode selection
pin. Connect this pin to a resistor divider from VCC and AGND for different MODE
options.
MODE
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is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS6243A/B-01 June 2019
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
