Supply Controller. RT8231A Datasheet

RT8231A Controller. Datasheet pdf. Equivalent

RT8231A Datasheet
Recommendation RT8231A Datasheet
Part RT8231A
Description Complete DDR Memory Power Supply Controller
Feature RT8231A; ® RT8231A/B Complete DDR Memory Power Supply Controller General Description The RT8231A/B provides.
Manufacture RICHTEK
Datasheet
Download RT8231A Datasheet




RICHTEK RT8231A
®
RT8231A/B
Complete DDR Memory Power Supply Controller
General Description
The RT8231A/B provides a complete power supply for
DDR2/DDR3/DDR3L/LPDDR3/DDR4/LPDDR4 memory
systems. It integrates a synchronous PWM Buck
controller with a 1.5A sink/source tracking linear regulator
and buffered low noise reference.
The PWM controller provides the low quiescent current,
high efficiency, excellent transient response, and high DC
output accuracy needed for stepping down high-voltage
batteries to generate low-voltage chipset RAM supplies
in notebook computers. The constant on-time PWM
control scheme handles wide input/output voltage ratios
with ease and provides 100ns instant-onresponse to
load transients while maintaining a relatively constant
switching frequency.
The RT8231A/B achieves high efficiency at a reduced cost
by eliminating the current-sense resistor found in
traditional current mode PWMs. Efficiency is further
enhanced by its ability to drive very large synchronous
rectifier MOSFETs. The Buck conversion allows this device
to directly step down high-voltage batteries for the highest
possible efficiency.
The 1.5A sink/source LDO maintains fast transient
response only requiring a 10μF ceramic output capacitor.
In addition, the LDO supply input is available externally
to significantly reduce the total power losses. The
RT8231A/B supports all of the sleep state controls placing
VTT at high-Z in S3 and discharging VDDQ, VTT and
VTTREF (soft-off) in S4/S5.
The RT8231A/B provides protections including OVP, UVP,
and thermal shutdown. The RT8231A/B is available in the
WQFN-20L 3x3 package.
Applications
DDR2/DDR3/DDR3L/LPDDR3/DDR4/LPDDR4 Memory
Power Supplies
Notebook computers
SSTL18, SSTL15 and HSTL bus termination
Pin Configuration
(TOP VIEW)
VTTGND
VTTSNS
GND
VTTREF
VDDQ
20 19 18 17 16
1 15 LGATE
2 14 PGND
3
GND
13 CS
4 21 12 VDD
5 11 VID
6 7 8 9 10
WQFN-20L 3x3
Simplified Application Circuit
VVDD
PGOOD
VTT
VDD
TON
RT8231A/B
UGATE
PGOOD
BOOT
VTT
VTTSNS
PHASE
LGATE
CS FB
VTTREF
S3
S5 VDDQ
VID GND VLDOIN
VIN
VVDDQ
Copyright ©2019 Richtek Technology Corporation. All rights reserved.
DS8231A/B-09 April 2019
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1



RICHTEK RT8231A
RT8231A/B
Features
PWM Controller
Adjustable Current Limit with Low-Side RDS(ON)
Sensing
Low Quiescent Supply Current
Quick Load-Step Response within 100ns
1% VVDDQ Accuracy Over Line and Load
Adjustable 0.675V to 3.3V Output Range for 1.8V
(DDR2), 1.5V (DDR3), 1.35V (DDR3L), 1.2V (LPDDR3),
1.2V (DDR4) and 1.1V (LPDDR4)
4.5V to 26V Battery Input Range
Resistor Adjustable Frequency
Over-/Under-Voltage Protection
Internal Voltage Ramp Soft-Start
Drives Large Synchronous Rectifier MOSFETs
Power Good Indicator
1.5A LDO (VTT), Buffered Reference (VTTREF)
Capable to Sink and Source Up to 1.5A
LDO Input Available to Optimize Power Losses
Requires Only 10μF Ceramic Output Capacitor
Integrated Divider Tracks 1/2 VDDQ for both VTT
and VTTREF
Accuracy ±20mV for both VTTREF and VTT
Supports High-Z in S3 and Soft-Off in S4/S5
RoHS Compliant and Halogen Free
Ordering Information
RT8231A/B
Package Type
QW : WQFN-20L 3x3 (W-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
VDDQ and VTT Discharge Control
A : Tracing Mode
B : Non-Tracking Mode
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.
Marking Information
RT8231AGQW
24=YM
DNN
24= : Product Code
YMDNN : Date Code
RT8231BGQW
3T=YM
DNN
3T= : Product Code
YMDNN : Date Code
Copyright ©2019 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS8231A/B-09 April 2019



RICHTEK RT8231A
RT8231A/B
Functional Pin Description
Pin No.
1
Pin Name
VTTGND
2 VTTSNS
3, 21
(Exposed Pad)
GND
4 VTTREF
Pin Function
Power ground for the VTT LDO.
Voltage sense input for the VTT LDO. Connect to the terminal of the VTT_LDO
output capacitor.
The exposed pad must be soldered to a large PCB and connected to GND for
maximum power dissipation.
VTTREF buffered reference output.
5
VDDQ
Reference input for VTT and VTTREF.
6 FB
7 S3
Feedback voltage input. Connect to a resistive voltage divider from VDDQ to
GND to adjust the output voltage.
VTT LDO enable control input. Do not leave this pin floating.
8 S5
PWM enable control input. Do not leave this pin floating.
9 TON
Set the UGATE on-time through a pull-up resistor connecting to VIN.
10
PGOOD
Power good open-drain output. In high state when VDDQ output voltage is within
the target range.
11 VID
Internal reference voltage setting.
12 VDD
Supply voltage input for the analog supply and LGATE gate driver.
13 CS
Current limit threshold setting input. Connect to GND through the voltage setting
resistor.
14 PGND Power ground for low-side MOSFET.
15
LGATE
Low-side gate driver output for VDDQ.
16
PHASE
Switch node. External inductor connection for VDDQ and behave as the current
sense comparator input for Low-Side MOSFET RDS(ON) sensing.
17
UGATE
High-side gate driver output for VDDQ.
18 BOOT Bootstrap supply for high-side gate driver.
19
VLDOIN
Power supply for VTT LDO.
20 VTT
Power output for the VTT LDO.
Copyright ©2019 Richtek Technology Corporation. All rights reserved.
DS8231A/B-09 April 2019
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3







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