RICHTEK RT9187C

®
RT9187C
600mA, Ultra-Low Dropout, CMOS Regulator
General Description
The RT9187C 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
RT9187C 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 RT9187C consumes less than 0.1μA in shutdown
mode. The other features include ultra-low dropout voltage,
high output accuracy, current limiting protection, and high
ripple rejection ratio. The RT9187C is available in the SOT23-5 package.
Ordering Information
RT9187C
Package Type
B : SOT-23-5
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.
`
Ultra-Low-Noise for RF Application
Ultra-Fast Response in Line/Load Transient
<0.1μ
μA 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 2.2μ
μF Output Capacitor Required for Stability
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
Pin Configurations
(TOP VIEW)
VOUT
Richtek products are :
`
Features
Suitable for use in SnPb or Pb-free soldering processes.
ADJ
5
4
2
3
VIN GND EN
SOT-23-5
Marking Information
40= : Product Code
40=DNN
DNN : Date Code
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9187C-00
June 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1
RT9187C
Typical Application Circuit
VIN
1 VIN
CIN
2.2µF
VOUT 5
RT9187C
ADJ
Chip Enable
R1
VOUT
COUT
2.2µF
4
3 EN
R2
GND
2
VOUT = VREF x ⎛⎜ 1 + R1 ⎞⎟ (V)
R2 ⎠
⎝
Ω to maintain regulation.
Note : The value of R2 should be less than 100kΩ
Function Pin Description
Pin No.
Pin Name
Pin Function
1
VIN
Voltage Input.
2
GND
Ground.
3
EN
Chip Enable (Active High).
4
ADJ
Output Voltage Feedback.
5
VOUT
Voltage Output.
Function Block Diagram
VIN
EN
EN
OTP
POR
BIAS
-
VREF
+
Current Limit
Quick start
VOUT
ADJ
GND
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS9187C-00
June 2012
RT9187C
Absolute Maximum Ratings
(Note 1)
Supply Input Voltage ------------------------------------------------------------------------------------------------------EN Input Voltage -----------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C
SOT-23-5 --------------------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2)
SOT-23-5, θJA ---------------------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------------Junction Temperature -----------------------------------------------------------------------------------------------------Storage Temperature Range --------------------------------------------------------------------------------------------ESD Susceptibility (Note 3)
HBM (Human Body Model) -----------------------------------------------------------------------------------------------
Recommended Operating Conditions
6V
6V
0.400W
250°C/W
260°C
150°C
−65°C to 150°C
2kV
(Note 4)
Supply Input Voltage ------------------------------------------------------------------------------------------------------EN Input Voltage -----------------------------------------------------------------------------------------------------------Junction Temperature Range --------------------------------------------------------------------------------------------Ambient Temperature Range ---------------------------------------------------------------------------------------------
2.5V to 5.5V
0V to 5.5V
−40°C to 125°C
−40°C to 85°C
Electrical Characteristics
(VIN = VOUT + 1V, VEN = VIN, CIN = COUT = 2.2μF (Ceramic), TA = 25°C, unless otherwise specified)
Parameter
Symbol
Test Conditions
Min
Typ
Max
Unit
0.784
0.8
0.816
V
Reference Voltage Tolerance
VREF
ADJ Pin Current
I ADJ
VADJ = VREF
--
10
100
nA
IQ
VEN ≥ VIH, IOUT = 0mA
--
300
400
μA
I STBY
VEN ≤ VIL,VIN = 3.3V
--
0.1
1
μA
I LIM
RLOAD = 0.5Ω, VIN = 3.3V
0.9
--
--
A
I OUT = 0.3A, VOUT = 5V
--
60
100
IOUT = 0.5A, VOUT = 5V
--
100
200
--
0.4
--
Quiescent Current
Standby Current
(Note 5)
(Note 6)
Current Limit
Dropout Voltage
(Note 7)
VDROP
Load Regulation
(Note 8)
ΔVLOAD
VIN = (VOUT + 0.5V)
10mA < I OUT < 0.5A
Logic-High
VIH
VIN = 3.3V
1.8
--
--
Logic-Low
VIL
VIN = 3.3V
--
--
0.6
EN Current
I EN
VIN = 3.3V, Enable
--
0.1
1
Power Supply f = 100Hz
Rejection Rate f = 10kHz
PSRR
I OUT = 300mA
--
−60
--
--
−50
--
Line Regulation
ΔVLINE
VIN = (VOUT + 0.5) to 5.5V,
I OUT = 1mA
--
--
0.3
%
Start-Up Time
t Start_Up
RLOAD = 3Ω
--
150
--
μs
--
170
--
--
30
--
EN Threshold
Voltage
Thermal Shutdown Temperature TSD
Thermal Shutdown Hysteresis
ΔTSD
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9187C-00
June 2012
mV
%/A
V
μA
dB
°C
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3
RT9187C
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. θJA is measured at TA = 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 IQ = IIN - IOUT under no
load condition (IOUT = 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
(VEN <0.6V).
Note 7. The dropout voltage is defined as VIN − VOUT, which is measured when VOUT is VOUT(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.
www.richtek.com
4
is a registered trademark of Richtek Technology Corporation.
DS9187C-00
June 2012
RT9187C
Typical Operating Characteristics
(COUT = 2.2μF/x5R, unless otherwise specified )
Dropout Voltage
Voltagevs.
vs.Load
LoadCurrent
Current
Dropout Voltage (mV)
200
Current Limit
VOUT = 2.8V
VIN = 3.3V, VOUT = 2.8V
160
TJ = 25°C
120
80
TJ = 125°C
IOUT
(500mA/Div)
TJ = −40°C
40
0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Time (1ms/Div)
Load Current (A)
Quiescent
Currentvs.
vs.Temperature
Temperature
Quiescent Current
Reference
Voltagevs.
vs.Temperature
Temperature
Reference Voltage
0.84
400
Quiescent Current (μA)
Reference Voltage (V)
0.83
0.82
0.81
0.80
0.79
0.78
0.77
350
300
250
200
150
VIN = 3.3V
100
0.76
-50
-25
0
25
50
75
100
-50
125
EN
EN Threshold
Threshold Voltage
Voltagevs.
vs.Temperature
Temperature
0
25
50
75
100
125
EN Pin Shutdown Response
1.0
Threshold Voltage (V)
-25
Temperature (°C)
Temperature (°C)
0.9
Rising
VEN
(2V/Div)
0.8
Falling
0.7
VOUT
(2V/Div)
0.6
VIN = 3.3V, VOUT = 2.8V, IOUT = 560mA
0.5
-50
-25
0
25
50
75
100
125
Time (500μs/Div)
Temperature (°C)
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9187C-00
June 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
5
RT9187C
Start Up
Line Transient Response
4.3
VIN (V)
3.3
VEN
(2V/Div)
10
VOUT
(2V/Div)
VOUT (mV)
0
-10
VIN = 3.3V to 4.3V, ILOAD : 300mA
IOUT = 0mA
Time (500μs/Div)
Time (10μs/Div)
PSRR
PSRR
Load Transient Response
0
IOUT
(200mA/Div)
PSRR (dB)
-20
VOUT
(50mV/Div)
-40
ILOAD = 100mA
-60
ILOAD = 56mA
VIN = 5V, IOUT = 10mA to 0.3A
VIN = VEN = 3.3V ± 50mV
-80
Time (100μs/Div)
10
0.01
100
0.1
1000
1
10000
10
100000
100
Frequency (kHz)
Region of Stable COUT ESR vs. Load Current
Regionof
ofStable
Stable CCOUT
ESR (Ω)
(Ω)
OUT ESR
Region
100
VIN = 3.3V
Unstable Range
10
1
Stable Range
0.1
0.01
0.001
0
0.1
0.2
0.3
0.4
0.5
Load Current (A)
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
6
is a registered trademark of Richtek Technology Corporation.
DS9187C-00
June 2012
RT9187C
Applications Information
Output Voltage Setting
Thermal Considerations
The voltage divider resistors can have values up to 100kΩ
because of the very high impedance and low bias current
of the sense comparator. The output voltage is set
according to the following equation :
For continuous operation, do not exceed absolute
maximum junction temperature. The maximum power
dissipation depends on the thermal resistance of the IC
package, PCB layout, rate of surrounding airflow, and
difference between junction and ambient temperature. The
maximum power dissipation can be calculated by the
following formula :
Chip Enable Operation
The RT9187C goes into sleep mode when the EN pin is in
a logic low condition. In this condition, the pass transistor,
error amplifier, and band gap are all turned off, reducing
the supply current to 1μA (max.). The EN pin can be directly
tied to VIN to keep the part on.
CIN and COUT Selection
Like any low dropout regulator, the external capacitors of
the RT9187C must be carefully selected for regulator
stability and performance. Using a capacitor of at least
2.2μF is suitable. The input capacitor must be located at
a distance of not more than 0.5 inch from the input pin of
the IC. Any good quality ceramic capacitor can be used.
However, a capacitor with larger value and lower ESR
(Equivalent Series Resistance) is recommended since it
will provide better PSRR and line transient response. The
RT9187C is designed specifically to work with low ESR
ceramic output capacitor for space saving and performance
consideration. Using a ceramic capacitor with value at least
2.2μF and ESR larger than 10mΩ on the RT9187C output
ensures stability. Nevertheless, the RT9187C can still work
well with other types of output capacitors due to its wide
range of stable ESR. “Typical Operating Characteristics”
shows the allowable ESR range as a function of load
current for various output capacitance. Output capacitors
with larger capacitance can reduce noise and improve load
transient response, stability, and PSRR. The output
capacitor should be located at a distance of not more than
0.5 inch from the output pin of the RT9187C.
PD(MAX) = (TJ(MAX) − TA) / θJA
where TJ(MAX) is the maximum junction temperature, TA is
the ambient temperature, and θJA is the junction to ambient
thermal resistance.
For recommended operating condition specifications, the
maximum junction temperature is 125°C. The junction to
ambient thermal resistance, θJA, is layout dependent. For
SOT-23-5 packages, the thermal resistance, θJA, is 250°C/
W on a standard JEDEC 51-3 single-layer thermal test
board. The maximum power dissipation at TA = 25°C can
be calculated by the following formula :
PD(MAX) = (125°C − 25°C) / (250°C/W) = 0.400W for
SOT-23-5 package
The maximum power dissipation depends on the operating
ambient temperature for fixed T J(MAX) and thermal
resistance, θJA. The derating curve in Figure 1 allows the
designer to see the effect of rising ambient temperature
on the maximum power dissipation.
0.45
Maximum Power Dissipation (W)1
VOUT = VREF × ⎛⎜ 1+ R1 ⎞⎟
⎝ R2 ⎠
where VREF is the reference voltage with a typical value of
0.8V. When the ADJ short to VOUT, there must be a
resistor (<100kΩ) from ADJ to GND.
Single-Layer PCB
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0.00
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 1. Derating Curve of Maximum Power Dissipation
Copyright © 2012 Richtek Technology Corporation. All rights reserved.
DS9187C-00
June 2012
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
7
RT9187C
Outline Dimension
H
D
L
B
C
b
A
A1
e
Dimensions In Millimeters
Dimensions In Inches
Symbol
Min
Max
Min
Max
A
0.889
1.295
0.035
0.051
A1
0.000
0.152
0.000
0.006
B
1.397
1.803
0.055
0.071
b
0.356
0.559
0.014
0.022
C
2.591
2.997
0.102
0.118
D
2.692
3.099
0.106
0.122
e
0.838
1.041
0.033
0.041
H
0.080
0.254
0.003
0.010
L
0.300
0.610
0.012
0.024
SOT-23-5 Surface Mount Package
Richtek Technology Corporation
5F, No. 20, Taiyuen Street, Chupei City
Hsinchu, Taiwan, R.O.C.
Tel: (8863)5526789
Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should
obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot
assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be
accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third
parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries.
www.richtek.com
8
DS9187C-00
June 2012