Data Sheet
1
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
General Description
The AP2121 series are positive voltage regulator ICs
fabricated by CMOS process. Each of these ICs con-
sists of a voltage reference, an error amplifier, a resis-
tor network for setting output voltage, a current limit
circuit for current protection and a chip-enable circuit
(5-pin products only).
The AP2121 series feature high supply voltage ripple
rejection, low dropout voltage, low noise, high output
voltage accuracy, and low current consumption which
make them ideal for use in various battery-powered
devices.
The AP2121 series have 1.2V, 1.3V, 1.5V, 1.8V, 2.5V,
2.8V, 2.85V, 3.0V, 3.2V and 3.3V versions.
The AP2121 are available in standard SOT-23-3, SOT-
23-5 and CSP-4 packages.
Features
·Low Dropout Voltage at IOUT=100mA: 150mV
Typical (Except 1.2V, 1.3V and 1.5V Versions)
·Low Standby Current: 0.1μA Typical
·Low Quiescent Current: 25μA Typical
·High Ripple Rejection: 70dB Typical （f=1kHz）
·Output Current: More Than 200mA (300mA
Limit)
·Extremely Low Noise: 30μVrms (10Hz to
100kHz)
·Excellent Line Regulation: 4mV Typical
·Excellent Load Regulation: 12mV Typical
·High Output Voltage Accuracy: ±2%
·Excellent Line Transient Response and Load
Transient Response
·Compatible with Low ESR Ceramic Capacitor (as
Low as 1μF)
Applications
·Mobile Phones, Cordless Phones
·Wireless Communication Equipment
·Portable Games
·Cameras, Video Recorders
·Sub-board Power Supplies for Telecom Equip-
ment
·Battery Powered Equipment
Figure 1. Package Types of AP2121
SOT-23-5SOT-23-3 CSP-4
Data Sheet
2
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Pin Configuration
Figure 2. Pin Configuration of AP2121 (Top View)
K Package
(SOT-23-5)
NC
VOUT
VIN
GND
CE
N Package
(SOT-23-3)
VIN
GND
VOUT
Pin Description
Pin Number
Pin Name Function
SOT-23-3 SOT-23-5 CSP-4
31 A2 V
IN Input voltage
1 2 B1 GND Ground
3 A1 CE Active high enable input pin. Logic high=enable, logic
low=shutdown
4 NC No connection
25 B2 V
OUT Regulated output voltage
J4/J4A Package
(CSP-4 (P 0.5)/CSP-4 (P 0.4))
3
21
1
2
34
5
A1 A2
B1 B2
Pin 1 Mark CE VIN
GND VOUT
Data Sheet
3
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Functional Block Diagram
Figure 3. Functional Block Diagram of AP2121
SOT-23-5/CSP-4
VREF
CURRENT LIMIT
VREF
CURRENT LIMIT
VIN
CE
VOUT
GND
2/B13/A1
1/A2 5/ B2
VIN VOUT
GND
1
32
SOT-23-3
Data Sheet
4
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Package Temperature
Range Condition
Part Number Marking ID Packing
Type
Lead Free Green Lead Free Green
SOT-23-3 -40 to 85oC
AP2121N-1.2TRE1 AP2121N-1.2TRG1 EF9 GF9 Tape & Reel
AP2121N-1.3TRE1 AP2121N-1.3TRG1 EG9 GG9 Tape & Reel
AP2121N-1.5TRE1 AP2121N-1.5TRG1 EF1 GF1 Tape & Reel
AP2121N-1.8TRE1 AP2121N-1.8TRG1 EF3 GF3 Tape & Reel
AP2121N-2.5TRE1 AP2121N-2.5TRG1 EF4 GF4 Tape & Reel
AP2121N-2.8TRE1 AP2121N-2.8TRG1 EF5 GF5 Tape & Reel
AP2121N-3.0TRE1 AP2121N-3.0TRG1 EF6 GF6 Tape & Reel
AP2121N-3.2TRE1 AP2121N-3.2TRG1 EF7 GF7 Tape & Reel
AP2121N-3.3TRE1 AP2121N-3.3TRG1 EF8 GF8 Tape & Reel
SOT-23-5 -40 to 85oC
Active High (Pull-down resistor built-in) AP2121AK-1.2TRE1 AP2121AK-1.2TRG1 E1T G1T Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-1.3TRE1 AP2121AK-1.3TRG1 E1R G1R Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-1.5TRE1 AP2121AK-1.5TRG1 E1Z G1Z Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-1.8TRE1 AP2121AK-1.8TRG1 E1U G1U Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-2.5TRE1 AP2121AK-2.5TRG1 E1V G1V Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-2.8TRE1 AP2121AK-2.8TRG1 E1W G1W Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-3.0TRE1 AP2121AK-3.0TRG1 E1X G1X Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-3.2TRE1 AP2121AK-3.2TRG1 E3Z G3Z Tape & Reel
Active High (Pull-down resistor built-in) AP2121AK-3.3TRE1 AP2121AK-3.3TRG1 E1Y G1Y Tape & Reel
Circuit Type
Package
E1: Lead Free
AP2121 -
TR: Tape and Reel
Ordering Information
1.5: Fixed Output 1.5V
2.5: Fixed Output 2.5V
N: SOT-23-3
2.85: Fixed Output 2.85V
K: SOT-23-5
A: Active High
(Pull-down resistor built-in)
Blank: No Enable Function
1.8: Fixed Output 1.8V
2.8: Fixed Output 2.8V
3.0: Fixed Output 3.0V
3.2: Fixed Output 3.2V
1.3: Fixed Output 1.3V
1.2: Fixed Output 1.2V
G1: Green
J4: CSP-4(P 0.5)
J4A: CSP-4 (P 0.4)
3.3: Fixed Output 3.3V
5
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Package Te mp era tu re
Range Condition
Part Number Marking ID Packing
Type
Lead Free Green Lead Free Green
CSP-4 -40 to 85oC
0.4 Pitch AP2121AJ4A-
1.2TRG1 CB Tape & Reel
0.4 Pitch AP2121AJ4A-
1.3TRG1 CC Tape & Reel
0.4 Pitch AP2121AJ4A-
1.5TRG1 CD Tape & Reel
0.4 Pitch AP2121AJ4A-
1.8TRG1 CE Tape & Reel
0.4 Pitch AP2121AJ4A-
2.5TRG1 CF Tape & Reel
0.4 Pitch AP2121AJ4A-
2.8TRG1 CG Tape & Reel
0.4 Pitch AP2121AJ4A-
2.85TRG1 DD Tape & Reel
0.4 Pitch AP2121AJ4A-
3.0TRG1 CH Tape & Reel
0.4 Pitch AP2121AJ4A-
3.2TRG1 DA Tape & Reel
0.4 Pitch AP2121AJ4A-
3.3TRG1 DB Tape & Reel
CSP-4 -40 to 85oC
0.5 Pitch AP2121AJ4-
1.2TRG1 BA Tape & Reel
0.5 Pitch AP2121AJ4-
1.3TRG1 BB Tape & Reel
0.5 Pitch AP2121AJ4-
1.5TRG1 BC Tape & Reel
0.5 Pitch AP2121AJ4-
1.8TRG1 BD Tape & Reel
0.5 Pitch AP2121AJ4-
2.5TRG1 BE Tape & Reel
0.5 Pitch AP2121AJ4-
2.8TRG1 BF Tape & Reel
0.5 Pitch AP2121AJ4-
2.85TRG1 DC Tape & Reel
0.5 Pitch AP2121AJ4-
3.0TRG1 BG Tape & Reel
0.5 Pitch AP2121AJ4-
3.2TRG1 BH Tape & Reel
0.5 Pitch AP2121AJ4-
3.3TRG1 CA Tape & Reel
Ordering Information (Continued)
BCD Semiconductor's Pb-free products, as designated with "E1" suffix in the part number, are RoHS compliant. Products with
"G1" suffix are available in green packages.
Data Sheet
6
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Parameter Symbol Value Unit
Input Voltage VIN 6.5 V
Enable Input Voltage VCE -0.3 to VIN+0.3 V
Output Current IOUT 300 mA
Junction Temperature TJ150 oC
Storage Temperature Range TSTG -65 to 150 oC
Lead Temperature (Soldering, 10sec) TLEAD 260 oC
Thermal Resistance (Junction to Ambient)
(Note 2) θJA
SOT-23-3 250
oC/W
SOT-23-5 250
CSP-4 126
ESD (Human Body Model) ESD 2000 V
ESD (Machine Model) ESD 200 V
Absolute Maximum Ratings (Note 1)
Parameter Symbol Min Max Unit
Input Voltage VIN 26 V
Operating Ambient Temperature Range TA -40 85 oC
Recommended Operating Conditions
Note 1: Stresses greater than those listed under "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
under "Recommended Operating Conditions" is not implied. Exposure to "Absolute Maximum Ratings" for extended periods
may affect device reliability.
Note 2: Absolute maximum ratings indicate limits beyond which damage to the component may occur. Electrical specifica-
tions do not apply when operating the device outside of its operating ratings. The maximum allowable power dissipation is a
function of the maximum junction temperature, TJ(max), the junction-to-ambient thermal resistance, θJA, and the ambient tem-
perature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using: PD(max)=(TJ(max) -
TA)/θJA. Exceeding the maximum allowable power dissipation will result in excessive die temperature.
7
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Electrical Characteristics
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=2.2V
1mA≤IOUT≤30mA 1.176 1.2 1.224 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=2.2V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
2.2V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 700 900
mV
IOUT=100mA 700 900
IOUT=150mA 700 900
IOUT=200mA 700 900
Quiescent Current IQVIN=2.2V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=2.2V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=2.2V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±120 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=2.2V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
AP2121-1.2 Electrical Characteristics
Data Sheet
8
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=2.3V
1mA≤IOUT≤30mA 1.274 1.3 1.326 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=2.3V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
2.3V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 600 800
mV
IOUT=100mA 600 800
IOUT=150mA 600 800
IOUT=200mA 600 800
Quiescent Current IQVIN=2.3V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=2.3V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=2.3V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±130 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=2.3V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
Electrical Characteristics (Continued)
AP2121-1.3 Electrical Characteristics
9
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=2.5V
1mA≤IOUT≤30mA 1.47 1.5 1.53 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=2.5V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
2.3V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 400 600
mV
IOUT=100mA 400 600
IOUT=150mA 400 600
IOUT=200mA 400 600
Quiescent Current IQVIN=2.5V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=2.5V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=2.5V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±150 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=2.5V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
AP2121-1.5 Electrical Characteristics
Electrical Characteristics (Continued)
Data Sheet
10
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=2.8V
1mA≤IOUT≤30mA 1.764 1.8 1.836 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=2.8V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
2.3V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 20 40
mV
IOUT=100mA 150 300
IOUT=150mA 200 400
IOUT=200mA 250 500
Quiescent Current IQVIN=2.8V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=2.8V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=2.8V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±180 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=2.8V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
Electrical Characteristics (Continued)
AP2121-1.8 Electrical Characteristics
11
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Electrical Characteristics (Continued)
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=3.5V
1mA≤IOUT≤30mA 2.45 2.5 2.55 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=3.5V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
3V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 20 40
mV
IOUT=100mA 150 300
IOUT=150mA 200 400
IOUT=200mA 250 500
Quiescent Current IQVIN=3.5V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=3.5V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=3.5V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±250 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=3.5V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
AP2121-2.5 Electrical Characteristics
Data Sheet
12
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=3.8V
1mA≤IOUT≤30mA 2.744 2.8 2.856 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=3.8V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
3.3V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 20 40
mV
IOUT=100mA 150 300
IOUT=150mA 200 400
IOUT=200mA 250 500
Quiescent Current IQVIN=3.8V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=3.8V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=3.8V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±280 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=3.8V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
Electrical Characteristics (Continued)
AP2121-2.8 Electrical Characteristics
13
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=3.85V
1mA≤IOUT≤30mA 2.793 2.85 2.907 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=3.85V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
3.3V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 20 40
mV
IOUT=100mA 150 300
IOUT=150mA 200 400
IOUT=200mA 250 500
Quiescent Current IQVIN=3.85V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=3.85V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=3.85V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±280 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC CSP-4 5oC/W
(VIN=3.85V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
Electrical Characteristics (Continued)
AP2121-2.85 Electrical Characteristics
Data Sheet
14
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=4V
1mA≤IOUT≤30mA 2.94 3.0 3.06 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=4V
1mA≤IOUT≤80mA 12 40 mV
Line Regulation VRLINE
3.5V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 20 40
mV
IOUT=100mA 150 300
IOUT=150mA 200 400
IOUT=200mA 250 500
Quiescent Current IQVIN=4V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=4V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=4V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±300 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=4V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
Electrical Characteristics (Continued)
AP2121-3.0 Electrical Characteristics
15
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Electrical Characteristics (Continued)
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=4.2V
1mA≤IOUT≤30mA 3.136 3.2 3.264 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=4.2V
1mA≤ IOUT≤ 80mA 12 40 mV
Line Regulation VRLINE
3.7V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 20 40
mV
IOUT=100mA 150 300
IOUT=150mA 200 400
IOUT=200mA 250 500
Quiescent Current IQVIN=4.2V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=4.2V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=4.2V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±320 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=4.2V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
AP2121-3.2 Electrical Characteristics
Data Sheet
16
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Parameter Symbol Conditions Min Typ Max Unit
Output Voltage VOUT
VIN=4.3V
1mA≤IOUT≤30mA 3.234 3.3 3.366 V
Input Voltage VIN 6V
Output Current IOUT VIN-VOUT=1V 200 mA
Load Regulation VRLOAD
VIN=4.3V
1mA≤ IOUT≤ 80mA 12 40 mV
Line Regulation VRLINE
3.8V≤VIN≤6V
IOUT=30mA 416mV
Dropout Voltage VDROP
IOUT=10mA 20 40
mV
IOUT=100mA 150 300
IOUT=150mA 200 400
IOUT=200mA 250 500
Quiescent Current IQVIN=4.3V, IOUT=0mA 25 50 μA
Standby Current ISTD
VIN=4.3V
VCE in OFF mode 0.1 1 μA
Power Supply
Rejection Ratio PSRR Ripple 0.5Vp-p, f=1kHz
VIN=4.3V 70 dB
Output Voltage
Temperature Coefficient
ΔVOUT/ΔT
IOUT=30mA
±330 μV/oC
(ΔVOUT/VOUT)/ΔT ±100 ppm/oC
Short Current Limit ILIMIT VOUT=0V 50 mA
RMS Output Noise VNOISE TA=25oC
10Hz ≤f≤100kHz 30 μVrms
CE "High" Voltage CE input voltage "High" 1.5 V
CE "Low" Voltage CE input voltage "Low" 0.25 V
CE Pull-down Resistance RPD 2.5 5 10 MΩ
Thermal Resistance
(Junction to Case) θJC
SOT-23-3 74
oC/W
SOT-23-5 74
CSP-4 5
(VIN=4.3V, TJ=25oC, CIN=1μF, COUT=1μF,
Bold
typeface applies over
-40
o
C
≤
T
J
≤
85
o
C,
unless otherwise specified.)
AP2121-3.3 Electrical Characteristics
Electrical Characteristics (Continued)
17
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Typical Performance Characteristics
Figure 4. Output Voltage vs. Output Current
Figure 6. Output Voltage vs. Output Current
Figure 5. Output Voltage vs. Output Current
Figure 7. Output Voltage vs. Output Current
0 50 100 150 200 250 300 350
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Output Voltage (V)
Output Current (mA)
AP2121-1.2
VIN=2V
VIN=2.5V
VIN=3V
0 50 100 150 200 250 300 350 400
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
AP2121-1.5
VIN= 2V
VIN= 2.5V
VIN= 4V
Output Voltage (V)
Output Current (mA)
0 50 100 150 200 250 300 350
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
Output Voltage (V)
Output Current (mA)
AP2121-1.8
VIN= 2.2V
VIN= 2.8V
VIN= 4V
0 50 100 150 200 250 300 350
0.0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
AP2121-2.5
VIN= 2.8V
VIN= 3.5V
VIN= 5V
Output Voltage (V)
Output Current (mA)
Data Sheet
18
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Typical Performance Characteristics (Continued)
Figure 9. Output Voltage vs. Input Voltage
Figure 10. Output Voltage vs. Input Voltage
01234567
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Output Voltage (V)
Input Voltage (V)
AP2121-1.2
IOUT=30mA
Figure 8. Output Voltage vs. Output Current
Figure 11. Dropout Voltage vs. Output Current
0 40 80 120 160 200
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Minimum Operating Requirement
Dropout Voltage (V)
Output Current (mA)
AP2121-1.2
0 50 100 150 200 250 300 350
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Output Voltage (V)
Output Current (mA)
AP2121-3.0
VIN=3.3V
VIN=4V
VIN=6V
19
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Typical Performance Characteristics (Continued)
Figure 13. Output Voltage vs. Junction Temperature
0 40 80 120 160 200
0.0
0.1
0.2
0.3
0.4
0.5
0.6
Dropout Voltage (V)
Output Current (mA)
AP2121-3.0
Figure 12. Dropout Voltage vs. Output Current
-25 0 25 50 75 100 125
2.90
2.92
2.94
2.96
2.98
3.00
3.02
3.04
3.06
3.08
3.10
AP2121-3.0
VIN=4V
IOUT=30mA
Output Voltage (V)
Junction Temperature (oC)
Figure 14. Output Voltage vs. Junction Temperature
-25 0 25 50 75 100 125
1.190
1.192
1.194
1.196
1.198
1.200
1.202
1.204
1.206
1.208
1.210
Output Voltage (V)
Junction Temperature (oC)
AP2121-1.2
VIN=2.2V
IOUT=30mA
Figure 15. Supply Current vs. Input Voltage
01234567
0
5
10
15
20
25
30
Supply Current (μA)
Input Voltage (V)
AP2121-1.2
IOUT=0mA
Data Sheet
20
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Typical Performance Characteristics (Continued)
Figure 17. Supply Current vs. Junction Temperature
01234567
0
10
20
30
40
50
60
Supply Current (μA)
Input Voltage (V)
AP2121-3.0
IOUT=0mA
Figure 16. Supply Current vs. Input Voltage
-25 0 25 50 75 100 125
0
5
10
15
20
25
30
35
40
Supply Current (μA)
Junction Temperature (oC)
AP2121-3.0
VIN=4V
IOUT=0mA
Figure 18. Supply Current vs. Junction Temperature
-25 0 25 50 75 100 125
0
5
10
15
20
25
30
35
40
Supply Current (μA)
Junction Temperature (oC)
AP2121-1.2
VIN=2.2V
IOUT=0mA
Figure 19. Line Transient
(Conditions: IOUT=30mA, CIN=1μF, C OUT=1μF)
Δ
V
OUT
(0.05V/Div) V
IN
( 1 V / D i v )
Time (100μs/Div)
AP2121-1.2
0
2.2
3.2
0.05
-0.05
4.2
21
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Typical Performance Characteristics (Continued)
Figure 21. Load Transient
(Conditions: VIN=2.2V, CIN=1μF, C OUT=1μF)
V
OUT
(0.1V/Div)
Time (200μs/Div)
AP2121-1.2
1.2
1.1
AP2121-3.0
Figure 20. Line Transient
(Conditions: IOUT=30mA, CIN=1μF, COUT=1μF)
AP2121-3.0
Time (200μs/Div)
Figure 22. Load Transient
(Conditions: VIN=4V, CIN=1μF, C OUT=1μF)
Time (20μs/Div)
Δ
V
OUT
(0.05V/Div) V
IN
( 1 V / D i v )
0
4
5
0.05
-0.05
61.3
I
OUT
(100mA/Div)
0
200
3.0
2.9
3.1
100
V
OUT
(0.1V/Div)
I
OUT
(100mA/Div)
0
200
100
Figure 23. PSRR vs. Frequency
10 100 1k 10k 100k
0
10
20
30
40
50
60
70
80
90
100
PSRR (dB)
Frequency (Hz)
AP2121-1.2
VIN=2.2V
IOUT=30mA
CIN=COUT=1μF
Data Sheet
22
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
10 100 1k 10k 100k
0
10
20
30
40
50
60
70
80
90
100
PSRR (dB)
Frequency (Hz)
AP2121-3.0
VIN=4V
IOUT=30mA
CIN=COUT=1μF
Typical Performance Characteristics (Continued)
Figure 24. PSRR vs. Frequency
23
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Typical Application
Figure 25. Typical Application of AP2121
Note: Filter capacitors are required at the AP2121's input and output. 1μF capacitor is required at the input. The
minimum output capacitance required for stability should be more than 1μF with ESR from 0.01Ω to 100Ω.
Ceramic capacitors are recommended.
VIN
AP2121-1.2
CIN
1μF
COUT
1μF
VOUT
VIN VOUT
GND
VIN
AP2121-3.0
CIN
1μF
COUT
1μF
VOUT
VIN VOUT
GND
CE NC
VIN=2.2V VOUT=1.2V
VOUT=3VVIN=4V
Data Sheet
24
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Mechanical Dimensions
SOT-23-3 Unit: mm(inch)
2.820(0.111)
3.020(0.119)
2.650(0.104)
2.950(0.116)
0.950(0.037)
TYP
0.300(0.012)
0.500(0.020)
1.500(0.059)
1.700(0.067)
1.800(0.071)
2.000(0.079)
0.300(0.012)
0.600(0.024)
0.100(0.004)
0.200(0.008)
0.000(0.000)
0.150(0.006)
0.900(0.035)
1.300(0.051)
1.450(0.057)
MAX.
0.200(0.008)
0
8
°
°
25
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Mechanical Dimensions (Continued)
SOT-23-5 Unit: mm(inch)
2.820(0.111)
2.650(0.104)
1.500(0.059)
0.000(0.000)
0.300(0.012)
0.950(0.037)
0.900(0.035)
0.100(0.004)
0.200(0.008)
0.300(0.012)
8°
0°
3.020(0.119)
1.700(0.067)
2.950(0.116)
0.400(0.016)
0.150(0.006)
1.300(0.051)
0.200(0.008)
0.600(0.024)
1.800(0.071)
2.000(0.079)
0.700(0.028)
REF
TYP
1.450(0.057)
MAX
Data Sheet
26
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Mechanical Dimensions (Continued)
CSP-4 (P 0.4) Unit: mm(inch)
0.960(0.038)
1.060(0.042)
Pin 1 Mark
0.940(0.037)
1.040(0.041)
0.400(0.016)
TYP.
0.400(0.016)
TYP.
Φ0.270(0.011)
TYP.
BA
1
2
0.550(0.022)
0.650(0.026)
0.180(0.007)
0.220(0.009)
27
Sep. 2012 Rev. 2. 5 BCD Semiconductor Manufacturing Limited
HIGH SPEED, EXTREMELY LOW NOISE LDO REGULATOR AP2121
Data Sheet
Mechanical Dimensions (Continued)
CSP-4 (P 0.5) Unit: mm(inch)
0.960(0.038)
1.060(0.042)
0.940(0.037)
1.040(0.041)
0.500(0.020)
TYP.
0.500(0.020)
TYP.
Φ0.320(0. 013)
TYP.
Pin 1 Mark
0.600(0.024)
0.700(0.028)
0.215(0.008)
0.255(0.010)
BA
1
2
IMPORTANT NOTICE
BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifi-
cations herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility fo r use of any its products for any
particular purpose, nor does BCD Semiconductor Man ufacturing Limited assume any liability arising out of the application or use
of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or
other rights nor the rights of others.
- Wafer Fab
Shanghai SIM-BCD Semiconductor Manufacturing Limited
800, Yi Shan Road, Shanghai 200233, China
Tel: +86-21-6485 1491, Fax: +86-21-5450 0008
BCD Semiconductor Manufacturing Limited
MAIN SITE
REGIONAL SALES OFFICE
Shenzhen Office
Shanghai SIM-BCD Semiconductor Manufacturing Co., Ltd. Shenzhen Office
Advanced Analog Circuits (Shanghai) Corporation Shenzhen Office
Room E, 5F, Noble Center, No.1006, 3rd Fuzhong Road, Futian District, Shenzhen 518026, China
Tel: +86-755-8826 7951
Fax: +86-755-8826 7865
Taiwan Office
BCD Semiconductor (Taiwan) Company Limited
4F, 298-1, Rui Guang Road, Nei-Hu District, Taipei,
Taiwan
Tel: +886-2-2656 2808
Fax: +886-2-2656 2806
USA Office
BCD Semiconductor Corporation
30920 Huntwood Ave. Hayward,
CA 94544, U.S.A
Tel : +1-510-324-2988
Fax: +1-510-324-2788
- IC Design Group
Advanced Analog Circuits (Shanghai) Corporation
8F, Zone B, 900, Yi Shan Road, Shanghai 200233, China
Tel: +86-21-6495 9539, Fax: +86-21-6485 9673
BCD Semiconductor Manufacturing Limited
http://www.bcdsemi.com
BCD Semiconductor Manufacturing Limited
IMPORTANT NOTICE
BCD Semiconductor Manufacturing Limited reserves the right to make changes without further notice to any products or specifi-
cations herein. BCD Semiconductor Manufacturing Limited does not assume any responsibility for use of any its products for any
particular purpose, nor does BCD Semiconductor Manufacturing Limited assume any liability arising out of the application or use
of any its products or circuits. BCD Semiconductor Manufacturing Limited does not convey any license under its patent rights or
other rights nor the rights of others.
- Wafer Fab
Shanghai SIM-BCD Semiconductor Manufacturing Co., Ltd.
800 Yi Shan Road, Shanghai 200233, China
Tel: +86-21-6485 1491, Fax: +86-21-5450 0008
MAIN SITE
REGIONAL SALES OFFICE
Shenzhen Office
Shanghai SIM-BCD Semiconductor Manufacturing Co., Ltd., Shenzhen Office
Unit A Room 1203, Skyworth Bldg., Gaoxin Ave.1.S., Nanshan District, Shenzhen,
China
Tel: +86-755-8826 7951
Fax: +86-755-8826 7865
Taiwan Office
BCD Semiconductor (Taiwan) Company Limited
4F, 298-1, Rui Guang Road, Nei-Hu District, Taipei,
Taiwan
Tel: +886-2-2656 2808
Fax: +886-2-2656 2806
USA Office
BCD Semiconductor Corp.
30920 Huntwood Ave. Hayward,
CA 94544, USA
Tel : +1-510-324-2988
Fax: +1-510-324-2788
- Headquarters
BCD Semiconductor Manufacturing Limited
No. 1600, Zi Xing Road, Shanghai ZiZhu Science-based Industrial Park, 200241, China
Tel: +86-21-24162266, Fax: +86-21-24162277