High-PSRR Low-Noise RF LDO
MD57XX Series
CMOS Voltage Regulator With ON/OFF Switch
300mA
The MD57XX series is a low-noise LDO that can supply up to 300 mA output
current. Designed to meet the requirements of RF and analog circuits, the
MD57XX series device provides low noise, high PSRR, low quiescent current, and
low line or load transient response figures. Using new innovative design
techniques, the MD57XX series offers ultra-low noise performance without a noise
bypass capacitor and the ability for remote output capacitor placement. response
figures with a 1-µF input and a 1-µF output ceramic capacitor
■ Features:
Input Voltage Range: 2.2 V to 5.5 V
Output Voltage Range: 1.2 V to 4.5 V
Stable With 1-µF Ceramic Input and
Output Capacitors
No Noise Bypass Capacitor Required
Remote Output Capacitor Placement
Current Limiter and Over Temperature
Protection
-40°C to 125°C Operating Junction
Temperature
Low Output Voltage Noise: 20µVRMS
High PSRR: 90dB@1kHz
Output Voltage Tolerance: ±2%
Low quiescent Current: 20uA
Low Dropout Voltage: 120mV@300mA
■
Applications:
Mobile Phones, Tablets
Digital Cameras and Audio Devices
Portable and Battery-Powered
Equipment
Portable Medical Equipment
Smart Meters and Field Transmitters
RF, PLL, VCO, and Clock Power
Supplies
IP Cameras
Drones
■ Typical Application:
VIN
+
CE
DC
-
VOUT
GND
CIN=1.0μF
+
MD57XX
VOUT
COUT=1.0μF
-
MD57XX Series
High-PSRR Low-noise RF LDO
■ Pin Configuration (Top View):
SOT 23-5L
VOUT
NC
5
4
DFN1*1-4L
VIN
EN
4
3
EP
5
1
VOUT
2
1
GND
VIN
2
3
GND
EN
■ Product Selections:
Product
Name
VOUT (V)
Package
Ordering
Name
MD5712
MD5715
MD5718
MD5721
MD5725
MD5728
MD5730
MD5733
MD5736
MD5712
MD5715
MD5718
MD5721
MD5725
MD5728
MD5730
MD5733
MD5736
1.2
1.5
1.8
2.1
2.5
2.8
3.0
3.3
3.6
1.2
1.5
1.8
2.1
2.5
2.8
3.0
3.3
3.6
DFN1*1-4L
DFN1*1-4L
DFN1*1-4L
DFN1*1-4L
DFN1*1-4L
DFN1*1-4L
DFN1*1-4L
DFN1*1-4L
DFN1*1-4L
SOT23-5L
SOT23-5L
SOT23-5L
SOT23-5L
SOT23-5L
SOT23-5L
SOT23-5L
SOT23-5L
SOT23-5L
MD57E12WB6
MD57E15WB6
MD57E18WB6
MD57E21WB6
MD57E25WB6
MD57E28WB6
MD57E30WB6
MD57E33WB6
MD57E36WB6
MD57E12QC3
MD57E15QC3
MD57E18QC3
MD57E21QC3
MD57E25QC3
MD57E28QC3
MD57E30QC3
MD57E33QC3
MD57E36QC3
Marking
5712
5715
5718
5721
5725
5728
5730
5733
5736
5712
5715
5718
5721
5725
5728
5730
5733
5736
Package
Information
Tape and Reel, 10000pcs
Tape and Reel, 3000pcs
Notes:
1* Customer can request to customize the output voltage ranged from 1.2V to 4. 5V if desired voltage is not found in the selections.
2* Customer can request customization of package choice.
3* Please pay attention to the MARKING of the product package type.
2 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Ordering Information
MD57 ①②③④⑤⑥⑦
e.g. MD57E33QC3
DESIGNATOR
ITEM
SYMBOL
DESCRIPTION
VOUT
NC
5
4
VIN
EN
4
①
PIN Configuration
E
3
EP
5
1
1
VIN
②③
④
⑤
⑥
⑦
2
GND
EN
VOUT
GND
e.g. 1.8V→②=1, ③=8
SOT23
Packages Type
DFN
Packages Count
e.g. A=3, B=4, C=5 ~
0=100, 1=1000, 2=2500,
Minimum Packing Quantity
0~6
3=3000, 4=4000, 5=5000,
6=10000
Customer can request customization of product
Output Voltage
18~
Q
W
A~Z
■ Absolute Maximum Ratings:
(Unless otherwise indicated: Ta=25℃)
PARAMETER
SYMBOL
RATINGS
UNITS
Input Voltage
VIN
-0.3 ~ 6.0
Output Voltage
VOUT
-0.3 ~ VIN+0.3V
Power Dissipation
PD
Thermal Resistance
RθJB (1)
Operating Ambient Temperature
Topr
-40 ~ +85
Storage Temperature
Tstg
-40 ~ +125
ESD Protection
ESD HBM
6000
SOT23-5L
250
DFN1*1-4L
200
SOT23-5L
180
DFN1*1-4L
160
Note: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
(1)
2
3
Mounted on JEDEC standard 4layer (2s2p) PCB test board
■ Notes on Use:
Input Capacitor (CIN): 1.0µF above
Output Capacitor (COUT):1.0µF above
3 / 12
V
mW
℃/W
℃
V
MD57XX Series
High-PSRR Low-noise RF LDO
■ Electrical Characteristics:
MD57XX Series
PARAMETER
SYMBOL
Output Voltage
VOUT(S)
Dropout Voltage*1
Line Regulation
Line Transient
VDROP
ΔVOUT
ΔVIN • VOUT(s)
VOUT_Line
Load Regulation
VOUT2
Load Transient
VOUT_Load
Temperature
Stability
ΔVOUT
Ta • VOUT(s)
GND Current
(VEN=VIN)
IGND
Shutdown Current
ISHUT
Input Voltage
Maximum Output
Current
VIN
(Unless otherwise indicated：Ta=25℃)
CONDITIONS
VIN=VOUT(S)+2.0V
IOUT=1mA, VOUT(S)＜2.0V
VIN=VOUT(S)+1.0V
IOUT=1mA, VOUT(S)≥2.0V
VEN=VIN, VOUT＜3V
IOUT=300mA
VEN=VIN, VOUT≥3V
IOUT=300mA
MIN.
VOUT(S)-0.03
VOUT(S)0.98
V
VOUT(S)1.02
130
mV
120
0.02
0.1
％/V
-1
mV
1
10
20
-40
40
VIN=VEN=VOUT(S)+1.0V
IOUT=1mA , -40℃≤Ta≤125℃
±100
no load
20
IOUT=300mA
470
VIN=5.5V, VEN=0
0.01
2.2
IOUTMAX
UNIT
VOUT(S)+0.03
IOUT=300mA to 1mA in 10µs
---
MAX.
VOUT(S)
VOUT(S)+1.0V≤VIN=VEN≤5.5V
IOUT=10mA
VIN= VOUT+1V to VOUT+2V
in 30us
VIN= VOUT+2V to VOUT+1V
in 30us
VIN=VEN=VOUT(S)+1.0V
1mA≤IOUT≤300mA
IOUT=1mA to 300mA in 10µs
TYP.
250
mV
mV
ppm/℃
30
µA
µA
0.1
µA
5.5
V
300
mA
Current Limit*2
ILIM
VIN=VEN=VOUT(S)+1.0V
VOUT = 0.95 ×VOUT(S)
500
mA
COUT Auto
Discharge
RDCHG
VEN=0, VOUT=VOUT(S)
240
Ω
f=1kHz, IOUT=20mA
94
Power Supply
Rejection Ratio
PSRR
Output noise
voltage
eN
Start-Up Time
TSTART
Overshoot on
Start-Up
EN ‘H’ Level
Voltage
EN ‘L’ Level
Voltage
EN ‘H’ Level
Current
EN ‘L’ Level
Current
Over Temperature
Protection
VOUT_Start-up
f=10kHz, IOUT=20mA
72
f=100kHz, IOUT=20mA
77
f=1MHz, IOUT=20mA
53
IOUT=20mA
20
From VEN>VENH to
VOUT=95% of VOUT
Stated as a percentage of
VOUT(S)
80
dB
µVRMS
150
µs
5
%
VENH
---
0.85
5.5
VENL
---
0
0.35
IENH
VIN=5.5V, VEN =VIN
-0.1
0.1
IENL
VIN=5.5V, VEN =0
-0.1
0.1
OTP
IOUT=1mA
V
µA
Notes：
1.
VDROP=VIN1 -（VOUT(S)× 0.98）where VIN1 is the input voltage when VOUT = VOUT(S)× 0.98.
2.
ILIM: Output current when VIN=VOUT(S)+1V and VOUT = 0.95*VOUT(S).
4 / 12
155
℃
MD57XX Series
High-PSRR Low-noise RF LDO
■ Typical Performance Characteristics:
Test Conditions: VIN=4.3V, VOUT=3.3V, CIN=1.0μF, COUT=1.0μF, Ta=25℃, unless otherwise indicated.
Supply Current vs. Input Voltage
VEN Thresholds vs. Input Voltage
Output Voltage vs. Temperature
Supply Current vs. Temperature
Output Voltage vs. Input Voltage
GND Current vs. Output Current
5 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Typical Performance Characteristics (Continued):
Test Conditions: VIN=4.3V, VOUT=3.3V, CIN=1.0μF, COUT=1.0μF, Ta=25℃, unless otherwise indicated.
Dropout Voltage vs. Output Current
Output Voltage vs. Output Current
Ch1=VOUT
Ch1=VOUT
Offset=4.3V
Ch2=VIN
Ch4=IOUT
Line Transient:
Load Transient:
(IOUT=10mA)
(IOUT=0mA~300mA~0mA)
Ch1=VOUT
Ch1=VOUT
Ch2=VEN
Ch2=VEN
EN Enable:
EN Enable:
(IOUT=0mA)
(IOUT=300mA)
6 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Typical Performance Characteristics (Continued):
Test Conditions: VIN=4.3V, VOUT=3.3V, CIN=1.0μF, COUT=1.0μF, Ta=25℃, unless otherwise indicated.
Power Supply Rejection Ratio
Noise Density Test
7 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Detailed Description:
1. Overview
Using new innovative design techniques, the MD57XX series offers ultra-low noise performance without
the need for a separate noise filter capacitor.
The MD57XX series is designed to perform with a single 1-µF input capacitor and a single 1-µF ceramic
output capacitor. With a reasonable PCB layout, the single 1-µF ceramic output capacitor can be placed
up to 10 cm away from the MD57XX series device.
2. Functional Block Diagram
VOUT
VIN
EN
POR
-
EN
-
+
RF
CF
RAD
+
+
-
VBG
1.2V
+
EN
EN
EN
1MΩ
+
-
VIH
GND
8 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Feature Description
1. Enable (EN)
The MD57XX series EN pin is internally held low by a 1-MΩ resistor to GND. The EN pin voltage must be
higher than the VENH threshold to ensure that the device is fully enabled under all operating conditions.
The EN pin voltage must be lower than the VENL threshold to ensure that the device is fully disabled and
the automatic output discharge is activated.
2. Low Output Noise
Any internal noise at the MD57XX series reference voltage is reduced by a first order low-pass RC filter
before it is passed to the output buffer stage. The low-pass RC filter has a –3 dB cut-off frequency of
approximately 0.1 Hz.
3. Output Automatic Discharge
The MD57XX series output employs an internal 240-Ω (typical) pulldown resistance to discharge the
output when the EN pin is low, and the device is disabled
4. Remote Output Capacitor Placement
The MD57XX series requires at least a 1-µF capacitor at the OUT pin, but there are no strict requirements
about the location of the capacitor in regards the OUT pin. In practical designs, the output capacitor may
be located up to 10 cm away from the LDO.
5. Over Temperature Protection (OTP)
Over temperature protection disables the output when the junction temperature rises to approximately
160°C which allows the device to cool. When the junction temperature cools to approximately 135°C, the
output circuitry enables. Based on power dissipation, thermal resistance, and ambient temperature, the
thermal protection circuit may cycle on and off. This thermal cycling limits the dissipation of the regulator
and protects it from damage as a result of overheating.
The over temperature protection circuitry of the MD57XX series has been designed to protect against
temporary thermal overload conditions. The OTP circuitry was not intended to replace proper heat-sinking.
Continuously running the MD57XX series device into thermal shutdown may degrade device reliability.
9 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Application and Implementation
The MD57XX series is designed to meet the requirements of RF and analog circuits, by providing low noise,
high PSRR, low quiescent current, and low line or load transient response figures. The device offers
excellent noise performance without the need for a noise bypass capacitor and is stable with input and
output capacitors with a value of 1 µF. The MD57XX series delivers this performance in industry standard
packages such as SOT23-5, for this device, are specified with an operating junction temperature (T J) of
–40°C to 125°C.
1. Typical Application
As the figure shows the typical application circuit for the MD57XX series. Input and output capacitances
may need to be increased above the 1 µF minimum for some applications.
VIN
+
CE
VOUT
DC
-
+
MD57XX
GND
VOUT
COUT=1.0μF
CIN=1.0μF
-
2. Design Requirements
DESIGN PARAMETER
Input voltage range
Output voltage
Output current
Output capacitor range
Input/Output capacitor ESR range
EXAMPLE VALUE
2.2 V to 5.5 V
1.8 V
300 mA
1 µF to 10 µF
5 to 500 mΩ
Notes:
1.
If the impedance of the power supply is high, which is caused by forgetting installing input capacitor or installing too
small value capacitor, the oscillation may occur.
2.
Pay attention to the operation conditions of input and output voltage and load current, such that the power consumption
in the IC should not exceed the allowable power consumption of the package even though the chip has short circuit
protection.
3. IC has a built-in anti-static protection (ESD) circuit, but please do not add excessive stress to the IC.
10 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Packaging Information
11 / 12
MD57XX Series
High-PSRR Low-noise RF LDO
■ Packaging Information (Continued)
DFN(1*1)-4L PACKAGE OUTLINE DIMENSIONS
For the newest datasheet, please see the website:
www.md-ic.com.cn
Version V1.0: 20200528
12 / 12
