© 2015 Semtech Corporation
POWER MANAGEMENT
1
SC4212L
High PSRR, Very Low Input, Very
Low Dropout, 1A Linear Regulator
Features
Input Voltage Range from 1.6V to 6.0V
150mV Maximum Dropout @ 1A
Adjustable Output from 0.5V with ± 1% Accuracy
High PSRR (76dB Typical at 1.8Vin to 0.5Vo, 1A)
Noise Bypass Pin
Programmable Soft-Start
12µA Quiescent Current in Shutdown
Enable Input
Power Good Indicator
Over Current and Over Temperature Protection
Reverse Blocking from Output to Input
Full Industrial Temperature Range
3mm x 3mm x 1mm MLPD-8 Package
Fully WEEE and RoHS Compliant
Applications
Telecom and Networking Cards
Motherboards and Peripheral Cards
Industrial Applications
Wireless Infrastructure
Medical Equipment
Description
The SC4212L is a high performance linear regulator
designed for applications requiring very low dropout
voltage at load currents up to 1 Ampere. It operates with
VIN as low as 1.6V and up to 6V, making it useful for a wide
range of different applications and rails. The output
voltage is programmable down to 0.5V, set via an external
resistor divider, or to a xed setting of 0.5V depending
upon how the FB pin is congured.
The SC4212L has an enable pin to further reduce power
dissipation while shut down. This device also offers an
active-high power good for the system to check the
output voltage. An external soft start capacitor can be
connected to the SS pin to program the profile of the
startup. Additionally, the device provides protection fea-
tures such as over current protection, over temperature
protection and reverse blocking from output to input. A
capacitor at the BYP pin can bypass the noise generated in
the internal bandgap reference in order to improve the
PSRR and the noise at the output. The SC4212L is available
in a 3mm x 3mm MLPD-8 package.
Typical Application Circuit
Rev. 2.0
S C 4 21 2 L
C
IN
C
O
E N
V IN
FB
V O
BYP
E N
V IN
V O
V O = 0 .5 V
R
2
S S
P G G N D
C
S S
C
BYP
P G
S C 4 21 2 L
C
IN
C
O
E N
V IN
FB
V O
BYP
E N
V IN
V O
R
2
S S
P G G N D
C
S S
C
BYP
P G
R
1
V O = 0 .5 (R 1+ R 2)
R2
C
3
* C3 is a placeholder
SC4212L
2
Pin Conguration
Marking Information
Ordering Information
Device Package
SC4212LMLTRC(1)(2) 3mm x 3mm x 1mm MLPD-8
SC4212LEVB Evaluation Board
Notes:
(1) Available in tape and reel only. A reel contains 3,000 devices.
(2) Available in lead-free package only. Device is WEEE and RoHS
compliant and halogen free.
3mm x 3mm x 1mm MLPD-8
θJA = 36.3°C/W
yyww = Datecode ( Example : 1352 )
xxxx = Semtech Lot No. ( Example : 2932 )
212L
yyww
xxxx
PG GND
FB
VO
BYP
8
7
6
5
1
2
3
4
EN
VIN
SS
TOP VIEW
SC4212L
3
Exceeding the above specications may result in permanent damage to the device or device malfunction. Operation outside of the parameters
specied in the Electrical Characteristics section is not recommended.
NOTES:
(1) Tested according to standard ANSI/ESDA/JEDEC JS-001-2012.
(2) Tested according to standard JESD-C101E.
(3) Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.
Absolute Maximum Ratings
VIN, VO, PG to GND (V) . . . . . . . . . . . . . . . . . . . . . . -0.3 to 6.5
EN, SS, BYP to GND (V) . . . . . . . . . . . . . . . . -0.3 to VIN + 0.3
FB to GND (V) . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to VIN + 0.3
Power Dissipation . . . . . . . . . . . . . . . . . . . . . Internally Limited
ESD Protection Level HBM(1) (kV) ................... 4
ESD Protection Level CDM(2) (kV) ................... 1
Recommended Operating Conditions
VIN (V) ................................... 1.6 ≤ VIN ≤ 6.0
Junction Temperature Range (°C) . . . . . . . . . -40 ≤ TJ ≤ +125
Output Current Range . . . . . . . . . . . . . . . . . . . 50 µA ≤ IO ≤ 1A
Thermal Information
Unless noted otherwise TJ = 25° C for typical, -40° C ≤ TJ ≤ 125° C for min and max. VEN = VIN, VFB = VO, VIN = 1.6V to 6.0V, CIN=10µF, COUT=10µF, CBYP
= 470nF.
Parameter Symbol Conditions Min Typ Max Units
VIN
VIN operating range(1) 1.6 6.0 V
Quiescent current IQ
VIN = 3.3V, IO = 0A 325 680 µA
IO = 1A 2 mA
VEN =0V 12 50 µA
Soft-Start
Soft-start source current ISS VIN = 3.3V 2 µA
tSS without external CSS 250 µs
Feedback
Feedback voltage(2) VFB IO = 10mA to 1A 0.495 0.500 0.505 V
Feedback pin current IFB VFB = VOUT 80 200 nA
VO
Line regulation(2) IO = 10mA 0.01 0.2 %/V
Electrical Characteristics
Thermal Resistance, Junction to Ambient (3) (°C/W) . . 36.3
Thermal Resistance, Junction to Case (°C/W) . . . . . . . . 3.77
Storage Temperature (°C) . . . . . . . . . . . . . . . . . . . -65 to +150
Peak IR Reflow Temperature (10s to 30s). . . . . . . . . . +260
SC4212L
4
Parameter Symbol Conditions Min Typ Max Units
Load regulation(2) IO = 10mA to 1A 0.21 1.0 %
Dropout voltage(3) VDO
IO =0.5A
1.6V ≤ VIN < 2.2V 86
mV
2.2V ≤ VIN ≤ 6.0V 75
IO = 1A
1.6V ≤ VIN < 2.2V 175
2.2V ≤ VIN ≤ 6.0V 150
Current limit ICL 1.2 2.6 A
Power Supply Rejection Ratio PSRR VIN = 1.8V, VO = 0.5V, IO
=1A, CBYP = 470nF
f = 100Hz 80
dB
f = 1kHz 76
f = 10kHz 64
f = 100kHz 43
f = 500kHz 32
f = 1MHz 26
EN
Enable pin current IEN
VEN = 0V, VIN = 1.6V to 6.0V 1.5 10 µA
VEN = VIN 80 200 nA
Enable pin threshold
VIH
VIN = 1.6V to 6.0V
1.2
V
VIL 0.4
Over Temperature Protection
High trip level THI 150 OC
Hysteresis THYST 10 OC
Power Good
PG threshold
Upper limit, VFB > internal 500mV reference 110
%
Lower limit, VFB < internal 500mV reference 90
PG pin leakage current VIN=3.3V 0.5 µA
PG resistance VIN=3.3V 53 Ω
Electrical Characteristics (continued)
Notes:
(1) Minimum VIN = VOUT + VDO or 1.6V, whichever is greater.
(2) Low duty cycle pulse testing with Kelvin connections required.
(3) VDO = VIN - VO when VFB = GND.
SC4212L
5
Pin Descriptions
Pin # Pin Name Pin Function
1 PG Power good output. Open drain, active high. Connect to a positive supply with a pullup resistor.
Leave this pin unconnected if not used.
2 EN
Enable input. Driving this pin high turns on the regulator. Driving this pin low shuts o the regula-
tor. If not driven from a control circuit, tie this pin directly to the VIN pin, or via a resistor up to
400kΩ.
3 VIN Input supply pin. A large bulk capacitance should be placed close to this pin to ensure that the
input supply does not sag below the minimum VIN.
4 SS Soft-start pin. Connecting a ceramic capacitor from this pin to GND sets the startup time. Refer to
the EC table (page 3) for the typical tSS with the external soft-start capacitor not populated.
5 BYP Bypass pin. Low noise performance is optimized by connecting a capacitor from this pin to GND.
6 VO Regulator output pin. Refer to the Applications Information section for output capacitor selection.
7 FB Input of the error amplier. This pin is used to set the output voltage (See typical Application
Circuits on page 1).
8 GND Ground pin.
THERMAL PAD The exposed pad enhances thermal performance and is not electrically connected inside the pack-
age. It is recommended to connect the exposed pad to the ground plane using multiple vias.
Block Diagram
O ver-current a n d
therm al sh utd o w n
C irc uitry
Enable
C irc uitry
R ev e rse P o larity
P rote ctio n C ircuitry
V
R E F
C irc uitry
G N D
FB
V OV IN
E N
P G
C irc uitry V
R E F
E N
V
FB
P G
S o ft-S tart
C irc uitry
BYP
S S
SC4212L
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Typical Characteristics
Dropout Voltage at Vin = 1.6V
Dropout Voltage at Vin = 6.0V
Dropout Voltage at Vin = 2.2V
Current Limit Threshold
Input Under-voltage Lockout Threshold Shutdown Current
1A
0.5A 0.5A
1A
0.5A
1A
Vin rising threshold
Vin falling threshold
Vin = 6.0V
Vin = 3.3V
Vin = 1.6V
Unless noted otherwise CIN=10µF/10V X7R 0805, COUT=10µF/10V X7R 0805.
SC4212L
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Typical Characteristics (Continued)
Quiescent Current
Output Rise Time
Output Rise Time
ENABLE Rising Threshold
ENABLE Falling Threshold PG Threshold
Unless noted otherwise CIN=10µF/10V X7R 0805, COUT=10µF/10V X7R 0805.
Io = 0A
Css = NP
Css = 10nF
Vin = 1.6V
Vin = 3.3V Vin = 6.0V
Upper Threshold
Lower Threshold
SC4212L
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Typical Characteristics (Continued)
Power Supply Ripple Rejection
Output Spectral Noise Density
Power Supply Ripple Rejection
Output Spectral Noise Density
Unless noted otherwise CIN=10µF/10V X7R 0805, COUT=10µF/10V X7R 0805.
CBYP = NP
Vin = 1.8V, Vo = 0.5V, Io = 1A
Vin = 1.8V, Vo = 0.5V, Io = 25mA
CBYP = 470nF
CBYP = NP, RL = 50Ω CBYP = 470nF, RL = 50Ω
Vn RMS (10Hz to 100kHz):
36.4µVrms, Vo = 0.5V
83.0µVrms, Vo = 1.2V
225.6µVrms, Vo = 3.3V
Vn RMS (10Hz to 100kHz):
15.7µVrms, Vo = 0.5V
36.9µVrms, Vo = 1.2V
85.7µVrms, Vo = 3.3V
CBYP = NP
CBYP = 470nF
SC4212L
9
Introduction
The SC4212L is intended for applications where high
current capability and very low dropout voltage are
required. It provides a very simple, low cost solution that
uses very little PCB area. Additional features include an
enable pin to allow for a very low power consumption in
standby mode, and a fully adjustable output.
VO Setting: VO = VREF
By connecting the FB pin directly to the VO pin, the output
voltage will be regulated to the 0.5V internal reference. In
this conguration, R2 should be 10kΩ.
VO Setting with External Resistors
The use of 1% resistors, and designing for a current ow ≥
50µA is recommended to ensure a well regulated output
(thus R2 ≤ 10kΩ). R1 can then be calculated from
R1 = R2 (VO-VREF)/VREF
Enable
Pulling this pin below 0.4V turns the regulator o, reduc-
ing the quiescent current to a fraction of its operating
value. Driving this pin high enables the regulator. A pull
up resistor ≤ 400kΩ should be connected from this pin to
the VIN pin in applications where the Enable pin is not
driven from a control circuit.
Input Capacitor
A 10µF X5R or X7R ceramic capacitor, along with a 0.1µF
ceramic decoupling capacitor is recommended to be
placed directly next to the VIN pin. This allows for the
device being some distance from the input source, reduc-
ing the input droop due to load transients and improving
load transient response. Additional capacitance may be
needed if large step, fast di/dt load transients are required
or the LDO is located far away from the input source.
Output Capacitor
A 10µF X5R or X7R ceramic capacitor, along with a 0.1µF
ceramic decoupling capacitor is recommended.
Applications Information
Soft-Start
Soft-start is achieved by using a voltage ramp as the
voltage reference for the internal error amplier during
startup. This voltage ramp is created by an internal 2µA
current source charging an external soft-start capacitor.
When the voltage ramp reaches 500mV, the voltage refer-
ence for the internal error amplier switches to the xed
500mV VREF. Thus, during soft-start, the output tracks the
internal voltage ramp, which limits the input inrush
current and provides a programmed soft-start prole for a
wide range of applications. The soft-start time tSS can be
calculated with the below equation:
tSS = 0.25x106CSS
Power Good
The power good output is an open-drain output which
requires a pull-up resistor. The SC4212L features an active-
high power good. During startup, the power good pin will
not be pulled high until the soft-start is completed. In any
case, the power good output will be low when the FB pin
voltage is not within 10% of VREF.
Over-Current and Thermal Shutdown
The over-current protection and thermal shutdown func-
tions protect the regulator against damage due to exces-
sive power dissipation. The SC4212L is designed to current
limit when the output current reaches 1.6A (typical). When
the load exceeds 1.6A, the output voltage is reduced to
maintain a constant current limit.
The thermal shutdown function limits the junction tem-
perature to a maximum of 150OC (typical). Thermal shut-
down turns o the regulator as the junction temperature
reaches the high trip level of 150OC. When the junction
temperature drops below 140OC (typical), the regulator is
turned on once again.
Thermal Considerations
The power dissipation in the SC4212L is roughly given by
the following equation:
PD = (VIN - VO)IO
SC4212L
10
The allowable power dissipation will be dependant upon
the thermal impedance achieved in the application. The
derating curve below is valid for the thermal impedance
specied in the Thermal Information section on page 3.
Figure 1. Power Derating Curve
Applications Information (Continued)
SC4212L
11
Outline Drawing — 3mm x 3mm MLPD-8
SC4212L
12
Land Pattern — 3mm x 3mm MLPD-8
X
P
Z
Y
H
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G
(C )
C O N T R O LLIN G D IM E N S IO N S A R E IN M ILLIM E TE R S (A N G LE S IN D EG R E E S ).
1.
3.
FA IL U R E T O D O S O M A Y C O M PR O M IS E T H E T H E R M A L A N D /O R
FU N C T IO N A L P E R FO R M AN C E O F TH E D E V IC E .
S H A L L B E C O N N E C T E D T O A S Y S T E M G R O U N D P L A N E .
TH E R M A L V IA S IN T H E L A N D P A T T E R N O F TH E EX P O S E D PA D
.030
.146
(.11 6)
.102
.087
.067
0.75
3.70
(2.9 5)
2.20
2.58
1.70
0.40
0.65.026
.016
TH IS LA N D P A T TE R N IS F O R R E F E R E N C E P U R P O S E S O N LY .
C O N S U L T Y O U R M A N U F A C T U R IN G G R O U P T O E N S U R E Y O U R
C O M P A N Y 'S M A N U F A C TU R IN G G U ID E LIN E S A R E M E T .
N O T E S :
2.
IN C H E S
D IM E N S IO N S
P
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X
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D IM M IL LIM E T E R S
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805) 498-2111 Fax: (805) 498-3804
www.semtech.com
Contact Information
SC4212L
13
© Semtech 2015
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