RT9991
Power Management IC for SSD
General Description
The RT9991 is a 3-CH PMIC for SSD (Solid-State Drive).
It integrates 3 synchronous buck converters and one
voltage detector.
The RT9991 provides 3 independent enable pins for
sequence control and auto discharge when powered off
on the power line of a NAND Flash.
The frequency can be up to 1.5MHz for Buck 1and Buck
2, and up to 2MHz for Buck 3, hence allowing the use of
smaller sized inductors to meet the space and height limit
in handheld applications.
To maximize power utilization, the RT9991 is designed
with extremely low quiescent current. The buck converter
can consume down to 70μA when operating in standby
mode.
The RT9991 is available in a VQFN-32L 5x5 package.
Features
Supply Input Voltage Range : 2.8V to 5.5V
Buck 1 / Buck 2
Adjustable Output Voltage for V
CORE
or DRAM
Cache
Output Current up to 1A
Switching Frequency : 1.5MHz
Buck 3
Adjustable Output Version for NAND Flash
Output Current up to 3A
Switching Frequency : 2MHz
Auto Discharge Function
Voltage Detector
Programmable Threshold Voltage
Open-Drain Reset Output
RoHS Compliant and Halogen Free
Applications
1.8/2.5 inch Solid-State Drives
Portable Devices
USB-Based Hand-Held Products
Ordering Information
RT9991
Package Type
QV : VQFN-32L 5x5 (V-Type)
Lead Plating System
G : Green (Halogen Free and Pb Free)
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.
Pin Configurations
(TOP VIEW)
GND
NC
NC
NC
FB2
EN2
VIN2
LX2
32 31 30 29 28 27 26 25
Marking Information
RT9991GQV : Product Number
DS9991-01 April 2011
NC
RESET
VDET
NC
FB1
EN1
VIN1
LX1
RT9991
GQV
YMDNN
YMDNN : Date Code
GND
LX3
LX3
LX3
VIN3
VIN3
EN3
FB3
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
33
24
23
22
GND
21
20
19
18
17
LX2
GND
GND
VIN2
VIN1
GND
GND
LX1
VQFN-32L 5x5
www.richtek.com
1
RT9991
Typical Application Circuit
RT9991
V
IN
5V
C1
15, 20 VIN1
21, 26 VIN2
5, 6
R7
R8
LX2
V
DD
3.3V
R9
43k
10
RESET
FB2
28
R4
64.9k
LX3
2, 3, 4
L3
1µH
R5
200k
FB3
8
R6
64.9k
C4
10µF x 2
V
OUT3
3.3V/3A
VIN3
FB1
13
R2
64.9k
24, 25
L2
2.2µH
R3
80k
C3
10µF
V
OUT2
1.8V/1A
LX1
16, 17
L1
2.2µH
R1
30k
C2
10µF
V
OUT1
1.2V/1A
11 VDET
Chip Enable
14 EN1
27 EN2
7 EN3
1, 18, 19, 22, 23, 32,
33 (Exposed Pad) GND
Function Block Diagram
RESET
VDET
0.7V
-
+
VIN1
EN1
Buck
Converter 1
LX1
FB1
VIN2
EN2
Buck
Converter 2
LX2
FB2
VIN3
EN3
Buck
Converter 3
LX3
GND
FB3
www.richtek.com
2
DS9991-01 April 2011
RT9991
Functional Pin Description
Pin No.
1, 18, 19, 22, 23, 32,
33 (Exposed Pad)
2, 3, 4
5, 6
7
8
9, 12, 29, 30, 31
10
11
13
14
15, 20
16, 17
21, 26
24, 25
27
28
Pin Name
GND
LX3
VIN3
EN3
FB3
NC
RESET
VDET
FB1
EN1
VIN1
LX1
VIN2
LX2
EN2
FB2
Pin Function
Ground. The exposed pad must be soldered to a large PCB and connected
to GND for maximum power dissipation.
Buck Converter 3 Switch Output (inductor connection point).
Buck Converter 3 Power Supply Input.
Buck Converter 3 Chip Enable (Active High).
Buck Converter 3 Feedback Input.
No Internal Connection.
Reset Output.
Threshold Voltage Detect Setting.
Buck Converter 1 Feedback Input.
Buck Converter 1 Chip Enable (Active High).
Buck Converter 1 Power Supply Input.
Buck Converter 1 Switch Output (inductor connection point).
Buck Converter 2 Power Supply Input.
Buck Converter 2 Switch Output (inductor connection point).
Buck Converter 2 Chip Enable (Active High).
Buck Converter 2 Feedback Input.
DS9991-01 April 2011
www.richtek.com
3
RT9991
Absolute Maximum Ratings
(Note 1)
−0.3V
to 6.5V
−0.3V
to (V
IN
+ 0.3V)
−0.3V
to 6.5V
2.778W
Supply Input Voltage, V
IN
-----------------------------------------------------------------------------------------
LX Pin Voltage -------------------------------------------------------------------------------------------------------
Other Pins Voltage -------------------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
VQFN-32L 5x5 ------------------------------------------------------------------------------------------------------
Package Thermal Resistance (Note 2)
VQFN-32L 5x5,
θ
JA
------------------------------------------------------------------------------------------------- 36°C/W
VQFN-32L 5x5,
θ
JC
------------------------------------------------------------------------------------------------ 6°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 Mode) --------------------------------------------------------------------------------------- 2kV
MM (Machine Mode) ----------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 4)
Supply Input Voltage,
V
IN
----------------------------------------------------------------------------------------- 2.8V to 5.5V
Junction Temperature Range -------------------------------------------------------------------------------------
−40°C
to 125°C
Ambient Temperature Range -------------------------------------------------------------------------------------
−40°C
to 85°C
Electrical Characteristics
(V
IN
= 5V, T
A
= 25°C, unless otherwise specified)
Parameter
Buck Converter 1
Quiescent Current
Shutdown Current
Feedback Reference Voltage
UVLO Under Voltage Lockout
Threshold
EN1 Threshold
Voltage
Logic-High
Logic-Low
Symbol
Test Conditions
Min
Typ
Max
Unit
μA
μA
V
V
V
V
A
MHz
μs
mΩ
mΩ
μA
μA
V
I
Q
I
SHDN
V
FB
V
UVLO
V
IH
V
IL
I
LIM
f
OSC
No Load, No Switching
EN = GND
V
IN
Rising
Hysteresis
--
--
--
--
--
1.5
--
1.3
70
0.2
0.8
2.1
0.1
--
--
1.7
1.5
250
250
260
70
0.2
0.8
--
--
--
--
--
V
IN
0.4
--
1.8
--
--
--
--
--
--
Peak Current Limit
Oscillator Frequency
Start-Up Time
P-MOSFET On Resistance
N-MOSFET On Resistance
BUCK CONVERTER 2
Quiescent Current
Shutdown Current
Feedback Reference Voltage
V
IN
= 3.6V, I
OUT
= 300mA
I
OUT
= 0mA. Time from active EN to
90% of V
OUT
1.2
--
--
--
--
--
--
R
DS(ON)_P
V
IN
= V
GS
= 3.6V, PWM Mode
R
DS(ON)_N
V
IN
= V
GS
= 3.6V, PWM Mode
I
Q
I
SHDN
V
FB
No Load, No Switching
EN = GND
To be continued
www.richtek.com
4
DS9991-01 April 2011
RT9991
Parameter
UVLO Under Voltage Lockout
threshold
EN2 Threshold
Voltage
Peak Current Limit
Oscillator Frequency
Start-Up Time
P-MOSFET On Resistance
N-MOSFET On Resistance
Buck Converter 3
Quiescent Current
Shutdown Current
Feedback Reference Voltage
UVLO Under Voltage Lockout
Threshold
EN3 Threshold
Voltage
Peak Current Limit
Oscillator Frequency
Start-Up Time
P-MOSFET On Resistance
N-MOSFET On Resistance
Voltage Detector
Voltage Detection Threshold
Voltage Detection Delay Time
Thermal Protections
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
T
SD
ΔT
SD
--
--
160
25
--
--
°C
°C
V
IN
Rising (L to H)
V
IN
Falling (H to L)
V
Delay
(L to H)
V
Delay
(H to L)
0.693
0.673
70
5
0.7
0.68
100
10
0.707
0.687
130
20
V
ms
μs
R
DS(ON)_P
Logic-High
Logic-Low
I
Q
I
SHDN
V
FB
V
UVLO
V
IH
V
IL
I
LIM
f
OSC
V
IN
= 3.6V, I
OUT
= 300mA
No Load. Time from active EN to
90% of V
OUT
V
IN
= V
GS
= 3.6V, PWM Mode
V
IN
Rising
Hysteresis
--
--
1.5
--
3.5
1.6
2000
--
--
No Load, No Switching
EN = GND
--
--
80
0.2
0.8
2.4
0.1
--
--
3.9
2
--
110
110
--
--
--
--
--
V
IN
0.4
--
2.4
--
--
--
μA
μA
V
V
V
A
MHz
μs
mΩ
mΩ
R
DS(ON)_P
Logic-High
Logic-Low
Symbol
V
UVLO
V
IH
V
IL
I
LIM
f
OSC
V
IN
= 3.6V, I
OUT
= 300mA
I
OUT
= 0mA Time from active EN to
90% of V
OUT
V
IN
= V
GS
= 3.6V, PWM Mode
V
IN
Rising
Hysteresis
Test Conditions
Min
--
--
1.5
--
1.3
1.2
--
--
--
Typ
2.1
0.1
--
--
1.7
1.5
250
250
260
Max
--
--
V
IN
0.4
--
1.8
--
--
--
Unit
V
V
A
MHz
μs
mΩ
mΩ
R
DS(ON)_N
V
IN
= V
GS
= 3.6V, PWM Mode
R
DS(ON)_N
V
IN
= V
GS
= 3.6V, PWM Mode
DS9991-01 April 2011
www.richtek.com
5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
