®
RT6219
4A, 23V, 500kHz, ACOT
TM
Synchronous Buck Converter
General Description
The RT6219 is a synchronous Buck converter with
Advanced Constant On-Time (ACOT
TM
) mode control which
provides a very fast transient response with no external
compensators. The RT6219 operates from 5V to 23V input
voltage, provides complete protection functions including
Over Current Protection(OCP), Under Voltage
Protection(UVP) and Over Voltage Protection(OVP). This
IC also provides a 1.5ms internal soft-start function and
an open-drain power good indicator.
Features
5V to 23V Input Voltage Range
Adjustable from 0.6V to 5V Output Range
Up to 98% Duty for 2S Battery Application
500kHz Switching Frequency
ACOT
TM
Mode Performs Fast Transient Response
Integrated MOSFETs
½
67mΩ of High-Side MOSFET
Ω
½
41mΩ of Low-Side MOSFET
Ω
Supports MLCC Output Capacitors
Internal Soft-Start (1.5ms typ)
Built-in OVP/UVP/OCP
Power Good Indicator
Thermal Shutdown
Ordering Information
RT6219
Package Type
QW : WDFN-10L 3x3 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
PWM Operation / VOUT Protection
A : with DEM/Latch
AH : with DEM/Hiccup
BL : without DEM/Latch
BH : without DEM/Hiccup
Note :
Richtek products are :
½
Applications
Laptop Computers
Tablet PCs
Networking Systems
Servers
Personal Video Recorders
Flat Panel Television and Monitors
Distributed Power Systems
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.
½
Simplified Application Circuit
V
IN
Enable
C
EN
V
SYS
R
BYP
C
BYP
PGND
VBYP
VIN
C
IN
EN
RT6219
SW
R1
FB
PGOOD
VCC
R
PGOOD
C
VCC
V
CC
R2
C
OUT
BOOT
C
B
L
V
OUT
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS6219-05 March 2017
www.richtek.com
1
RT6219
Marking Information
RT6219AGQW
6K= : Product Code
RT6219AHGQW
7S= : Product Code
YMDNN : Date Code
6K=YM
DNN
7S=YM
DNN
YMDNN : Date Code
RT6219BLGQW
7Q= : Product Code
RT6219BHGQW
7R= : Product Code
YMDNN : Date Code
7Q=YM
DNN
7R=YM
DNN
YMDNN : Date Code
Pin Configurations
(TOP VIEW)
PGOOD
VBYP
VIN
EN
FB
PGND
1
2
3
4
5
10
9
8
7
6
11
SW
SW
SW
BOOT
VCC
WDFN-10L 3x3
Functional Pin Description
Pin No.
1
2
3
4
5
6
Pin Name
PGOOD
VBYP
VIN
EN
FB
VCC
Pin Function
Open-Drain Power Good Indicator Output.
Switch Over Input Supply Voltage for VCC. A low pass filter should be connected
to AGND, if VBYP is applied. If VBYP is not used, then connect to AGND. Do not
connect to VCC pin.
Power Input Connect to High-Side MOSFET Drain.
Enable Control Input. Do not leave this pin floating. The slew rate of EN is
recommended to be slower than 4.8V/s.
Feedback Voltage Input.
5V Linear Regulator Output for Internal Control Circuit. Bypass V
CC
to AGND
with a 2.2F capacitor. V
CC
can only supply internal circuits. Do not connect to
external loads.
Bootstrap Supply for High-Side Gate Driver. A capacitor is needed to drive the
power switch's gate above the supply voltage. It is connected between the SW
and BOOT pins to form a floating supply across the power switch driver.
Switch Node.
Power Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
7
8, 9, 10
11
(Exposed Pad)
BOOT
SW
PGND
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS6219-05 March 2017
RT6219
Function Block Diagram
VCC
VBYP
V
CC
POR &
Reference
Soft-Start
V
CC
Switch-Over
On-Time
One shot
Min off Time
V
IN
BOOT
FB
V
REF
V
FB
+
+
-
Gate
Control
Logic
SW
V
CC
EN
PGND
SW
V
OC
+
-
OCP
PGOOD
125% x V
REF
-
+
OVP
-
+
Fault
Logic
POK
58% x V
REF
+
-
PGND
91.5% x V
REF
UVP
V
CC
V
CC
Regulator
VIN
Operation
Overall
The RT6219 is a synchronous step-down converter with
advanced constant on-time control mode. Using the
ACOT
TM
control mode can reduce the output capacitance
and provide fast transient response. It can minimize the
component size without additional external compensation
network.
Internal VCC Regulator
The regulator provides 5V power to supply the internal
control circuit. Connecting a 2.2μF ceramic capacitor for
decoupling and stability is required.
Soft-Start
In order to prevent the converter output voltage from
overshooting during the startup period, the soft-start
function is necessary. The soft-start time is internal setting
and the duration is around 1.5ms.
VCC Switch-Over
The internal regulator output will switch over to VBYP if
VBYP level is higher than 4.6V.
Power Off
There is an internal discharging circuit to discharge the
residual charge of output capacitor when converter is power
off.
OCP
The inductor valley current is monitored cycle-by-cycle
via the internal swiches, preventing an on-time until the
current drops below the current limit.
Power Good
After soft-start is finished, the power good output goes
high. The PGOOD pin is an open-drain output.
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS6219-05 March 2017
www.richtek.com
3
RT6219
Absolute Maximum Ratings
(Note 1)
VIN to PGND --------------------------------------------------------------------------------------------------
−0.3V
to 27V
SW to PGND --------------------------------------------------------------------------------------------------
−0.3V
to (V
IN
+ 0.3V)
<30ns -----------------------------------------------------------------------------------------------------------
−5V
to 28V
BOOT to PGND ----------------------------------------------------------------------------------------------- (V
SW
−
0.3V) to (V
SW
+ 6V)
EN to PGND ---------------------------------------------------------------------------------------------------
−0.3V
to 27V
FB to PGND ---------------------------------------------------------------------------------------------------
−0.3V
to 27V
VBYP to PGND -----------------------------------------------------------------------------------------------
−0.3V
to 5.3V
VCC, PGOOD to PGND ------------------------------------------------------------------------------------
−0.3V
to 6V
Power Dissipation, P
D
@ T
A
= 25°C
WDFN-10L 3x3 ------------------------------------------------------------------------------------------------ 3.28W
Package Thermal Resistance (Note 2)
WDFN-10L 3x3,
θ
JA
------------------------------------------------------------------------------------------ 30.5°C/W
WDFN-10L 3x3,
θ
JC
------------------------------------------------------------------------------------------ 7.5°C/W
Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------ 260°C
Junction Temperature ---------------------------------------------------------------------------------------- 150°C
Storage Temperature Range -------------------------------------------------------------------------------
−65°C
to 150°C
ESD Susceptibility (Note 3)
HBM (Human Body Model) --------------------------------------------------------------------------------- 2kV
(Note 4)
Recommended Operating Conditions
Supply Input Voltage, VIN ---------------------------------------------------------------------------------- 5V to 23V
Junction Temperature Range -------------------------------------------------------------------------------
−40°C
to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------
−40°C
to 85°C
Electrical Characteristics
(V
IN
= 12V, T
A
= 25°C, unless otherwise specified)
Parameter
Supply Current
Shutdown Current
Quiescent Current
Switch On-Resistance
Switch On-Resistance
Current Limit
Current Limit
Switching Frequency
Minimum Off-Time
Symbol
V
EN
= 0V
Test Conditions
Min
--
Typ
2.5
100
110
67
41
6
500
200
Max
5
130
150
--
--
8.3
550
--
Unit
A
A
V
EN
= 2V, No
Switching
R
DS(ON)_H
V
BOOT
– V
SW
= 5V
R
DS(ON)_L
I
OC
f
SW
T
OFF
(RT6219A/AH)
(RT6219BL/BH)
--
--
--
--
m
Valley current of low-side switch
4.5
450
--
A
kHz
ns
Switching Frequency and Minimum Off Timer
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS6219-05 March 2017
RT6219
Parameter
Protections
OVP Trip Threshold
OVP Propagation Delay
UVP Trip Threshold
UVP Propagation Delay
Reference and Soft-Start
Feedback Reference Voltage
Soft-Start Time
Enable and UVLO
EN Input High Voltage
EN Hysteresis
EN Input Current
VCC UVLO Rising
VCC UVLO Hysteresis
VCC Regulator
VCC Regulator
VCC Switch Over Threshold to
VBYP
VCC Switch Over Hysteresis
Switch Over On-Resistance
Power Good Indicator
PGOOD Threshold From Lower
PGOOD Low Hysteresis
PGOOD Low to High Delay
PGOOD Leakage Current
Thermal Shutdown
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
T
SD
T
J
Rising
135
--
150
25
--
--
°C
°C
T
PGDLY
Sink 4mA
V
PGOOD
= 5V
I
PGLEAK
PGOOD Sink Current Capability V
PGSINK
V
OUT
Rising
V
OUT
Falling
86.5
--
--
--
--
91.5
10
0.5
--
--
96.5
--
--
0.4
100
%
%
ms
V
nA
V
VCC
V
BYP
Rising Edge
4.805
4.4
--
--
5
4.6
200
3
5.295
4.8
--
5
V
V
mV
V
ENH
V
ENHYS
I
EN
V
CCUVLO
V
CCHYS
V
EN
= 2V
V
EN
= 0V
1.25
--
--
--
--
--
1.35
200
1
0
4.2
400
1.45
--
--
--
--
--
V
mV
A
V
mV
V
REF
T
SS
From EN high to PGOOD high
0.594
1
0.600
1.5
0.606
2
V
ms
V
OVP
T
OVPDLY
V
UVP
T
UVPDLY
With respect to output voltage
With respect to output voltage
120
--
53
--
125
5
58
5
130
--
63
--
%
s
%
s
Symbol
Test Conditions
Min
Typ
Max
Unit
Note 1.
Stresses beyond those listed
“Absolute
Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2.
θ
JA
is measured at T
A
= 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7.
Note 3.
Devices are ESD sensitive. Handling precaution is recommended.
Note 4.
The device is not guaranteed to function outside its operating conditions.
Copyright
©
2017 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS6219-05 March 2017
www.richtek.com
5