®
RT9187B
600mA, Ultra-Low Dropout, Ultra-Fast CMOS LDO Regulator
General Description
The RT9187B is a high-performance, 600mA LDO regulator,
offering extremely high PSRR and ultra-low dropout. This
chip is ideal for portable RF and wireless applications
with demanding performance and space requirements.
A noise reduction pin is also available for further reduction
of output noise. Regulator ground current increases only
slightly in dropout, further prolonging the battery life. The
RT9187B also works well with low-ESR ceramic
capacitors, reducing the amount of board space necessary
for power applications, critical in hand-held wireless
devices.
The RT9187B consumes less than 0.1μA in shutdown
mode and has fast turn-on time for less than 40μs. The
other features include ultra-low dropout voltage, high
output accuracy, current limiting protection, and high ripple
rejection ratio. The RT9187B is available in the SOT-23-5
package.
Features
Ultra-Low-Noise for RF Application
Ultra-Fast Response in Line/Load Transient
Quick Start-Up (Typically 40μs)
μ
μ
<0.1μA Standby Current When Shutdown
Low Dropout : 100mV at 500mA
Wide Operating Voltage Ranges : 2.5V to 5.5V
TTL-Logic-Controlled Shutdown Input
Current Limiting Protection
Thermal Shutdown Protection
Only 2.2μF Output Capacitor Required for Stability
μ
High Power Supply Rejection Ratio
RoHS Compliant and Halogen Free
Applications
CDMA/GSM Cellular Handsets
Battery-Powered Equipment
Laptop, Palmtops, Notebook Computers
Hand-Held Instruments
Mini PCI & PCI-Express Cards
PCMCIA & New Cards
Portable Information Appliances
Ordering Information
RT9187B
Package Type
B : SOT-23-5
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)
VOUT
5
2
ADJ
4
3
VIN GND EN
SOT-23-5
Marking Information
04= : Product Code
04=DNN
DNN : Date Code
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9187B-03 March 2012
www.richtek.com
1
RT9187B
Typical Application Circuit
V
IN
1 VIN
C
IN
2.2µF
VOUT 5
RT9187B
ADJ
Chip Enable
3 EN
GND
2
4
R2
R1
V
OUT
C
OUT
2.2µF
V
OUT
= 0.8 x (
1+
R
1
) Volts
R
2
Note : The value of R2 should be less than 80kΩ to maintain regulation.
Ω
Function Pin Description
Pin No.
1
2
3
4
5
VIN
GND
EN
ADJ
VOUT
Pin Name
Voltage Input.
Ground.
Chip Enable (Active High).
Output Voltage Feedback.
Voltage Output.
Pin Function
Function Block Diagram
VIN
EN
EN
OTP
POR
BIAS
-
V
REF
+
Current Limit
Quick start
VOUT
ADJ
GND
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS9187B-03 March 2012
RT9187B
Absolute Maximum Ratings
(Note 1)
6V
6V
0.400W
250°C/W
260°C
Supply Input Voltage -------------------------------------------------------------------------------------------------------
EN Input Voltage ------------------------------------------------------------------------------------------------------------
Power Dissipation, P
D
@ T
A
= 25°C
SOT-23-5 ---------------------------------------------------------------------------------------------------------------------
Package Thermal Resistance (Note 2)
SOT-23-5,
θ
JA
----------------------------------------------------------------------------------------------------------------
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------------
Junction Temperature ------------------------------------------------------------------------------------------------------ 150°C
Storage Temperature Range ---------------------------------------------------------------------------------------------
−65°C
to 150°C
ESD Susceptibility (Note 3)
HBM --------------------------------------------------------------------------------------------------------------------------- 2kV
MM ----------------------------------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 4)
Supply Input Voltage ------------------------------------------------------------------------------------------------------- 2.5V to 5.5V
EN Input Voltage ------------------------------------------------------------------------------------------------------------ 0V to 5.5V
Junction Temperature Range ---------------------------------------------------------------------------------------------
−40°C
to 125°C
Ambient Temperature Range ---------------------------------------------------------------------------------------------
−40°C
to 85°C
Electrical Characteristics
Parameter
Reference Voltage Tolerance
ADJ Pin Current
Quiescent Current
Standby Current
Current Limit
Dropout Voltage
Load Regulation
EN Threshold
Voltage
(Note 7)
(Note 8)
Logic-High
Logic-Low
(Note 5)
(Note 6)
(V
IN
= V
OUT
+ 1V, V
EN
= V
IN
, C
IN
= C
OUT
= 2.2μF (Ceramic),
T
A
= 25°C, unless otherwise specified)
Symbol
V
REF
I
ADJ
I
Q
I
STBY
I
LIM
V
DROP
ΔV
LOAD
V
IH
V
IL
I
EN
PSRR
ΔV
LINE
t
Start_Up
ΔT
SD
Test Conditions
V
ADJ
= V
REF
V
EN
≥
V
IH
, I
OUT
= 0mA
V
EN
≤
V
IL
,V
IN
= 3.3V
R
LOAD
= 0.5Ω, V
IN
= 3.3V
I
OUT
= 0.3A, V
OUT
= 5V
I
OUT
= 0.5A, V
OUT
= 5V
V
IN
= (V
OUT
+ 0.5V)
10mA < I
OUT
< 0.5A
V
IN
= 3.3V
V
IN
= 3.3V
V
IN
= 3.3V, Enable
I
OUT
= 300mA
V
IN
= (V
OUT
+ 0.5) to 5.5V,
I
OUT
= 1mA
R
LOAD
= 3Ω
Min
0.784
--
--
--
2
--
--
--
1.8
--
--
--
--
--
--
--
--
Typ
0.8
10
380
0.1
--
60
100
0.4
--
--
0.1
−60
−50
--
40
170
30
Max
0.816
100
500
1
--
100
200
--
--
0.6
1
--
--
0.3
--
--
--
Unit
V
nA
μA
μA
A
mV
%/A
V
μA
dB
%
μs
°C
Enable Pin Current
Power Supply f = 100Hz
Rejection Rate f = 10kHz
Line Regulation
Start-Up Time
Thermal Shutdown Hysteresis
Thermal Shutdown Temperature T
SD
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9187B-03 March 2012
www.richtek.com
3
RT9187B
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 low effective thermal conductivity single-layer test board per JEDEC 51-3.
Note 3.
Devices are ESD sensitive. Handling precaution is recommended.
Note 4.
The device is not guaranteed to function outside its operating conditions.
Note 5.
Quiescent, or ground current, is the difference between input and output currents. It is defined by I
Q
= I
IN
- I
OUT
under no
load condition (I
OUT
= 0mA). The total current drawn from the supply is the sum of the load current plus the ground pin
current.
Note 6.
Standby current is the input current drawn by a regulator when the output voltage is disabled by a shutdown signal
(V
EN
<0.6V).
Note 7.
The dropout voltage is defined as V
IN
−
V
OUT
, which is measured when V
OUT
is V
OUT(NORMAL)
−
100mV.
Note 8.
Regulation is measured at constant junction temperature by using a 2ms current pulse. Devices are tested for load
regulation in the load range from 10mA to 0.5A.
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
4
DS9187B-03 March 2012
RT9187B
Typical Operating Characteristics
(C
OUT
= 2.2μF/x5R, unless otherwise specified )
Quiescent Current vs. Temperature
500
Quiescent Current vs. Input Voltage
500
V
IN
= 3.3V
V
IN
= 3.3V
Quiescent Current (µA)
-50
-25
0
25
50
75
100
125
Quiescent Current (µA)
400
400
300
300
200
200
100
100
0
0
3
3.5
4
4.5
5
5.5
Temperature (°C)
Input Voltage (V)
Dropout Voltage vs. Load Current
150
Current Limit
V
IN
= 3.3V
5
V
IN
= 5V, V
OUT
= 3.3V
Dropout Voltage (mV)
120
Output Current (A)
4
3
2
1
0
90
T
J
= 25°C
60
T
J
= 125°C
T
J
=
−40°C
30
0
0.0
0.1
0.2
0.3
0.4
0.5
Time (1ms/Div)
Load Current (A)
EN Pin Shutdown Response
V
IN
= 3.3V, I
LOAD
: 500mA
10
4
Start Up
V
EN
(V)
5
0
V
EN
(V)
2
0
4
2
V
OUT
(V)
2
0
V
OUT
(V)
1
0
V
IN
= 3.3V
I
LOAD
: 500mA
Time (100μs/Div)
Time (25μs/Div)
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS9187B-03 March 2012
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
