SEMTECH SC4212_11

SC4212
Very Low Input /Very Low Dropout
1Amp Regulator With Enable
POWER MANAGEMENT
Features
Description
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The SC4212 is a high performance positive voltage regulator designed for applications requiring very low input
voltage and very low dropout voltage at up to 1 Ampere.
It operates with a VIN as low as 1.5V, with output voltage
programmable as low as 0.5V. The SC4212 features ultra
low dropout, ideal for applications where VOUT is very
close to VIN. Additionally, the SC4212 has an enable pin
to further reduce power dissipation while shutdown. The
SC4212 provides excellent regulation over variations in
line, load and temperature.
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Input voltage as low as 1.5V
400mV dropout @ 1A
Adjustable output from 0.5V
Over current and over temperature protection
Enable pin
10μA quiescent current in shutdown
Low reverse leakage (output to input)
Full industrial temperature range
Pb Free, Halogen Free and WeEE/RoHS Compliant
Applications
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Telecom/Networking cards
Motherboards/Peripheral cards
Industrial Applications
Wireless infrastructure
Set top boxes
Medical equipment
Notebook computers
Battery powered systems
The SC4212 is available in a 3 x 3 MLPD-8 package. The
output voltage can be set via external divider or to a
fixed setting of 0.5V depending upon how the FB pin
is configured.
Typical Application Circuit
SC4212
SC4212
Rev. 4.0
© 2011 Semtech Corporation
1
SC4212
Pin Configuration
Ordering Information
Part Number
NC
8
1
GND
SC4212MLTRT(1)(2)
Package
3mm x 3mm x 1mm MLPD-8
TOP VIEW
SC4212EVB
EN
2
7
FB
VIN
3
6
VOUT
NC
4
5
NC
Evaluation Board
Notes:
(1) Only available in tape and reel packaging. A reel contains 3000 devices.
(2) Device is Pb Free, Halogen Free, and WEEE/RoHS Compliant.
T
3mm x 3mm x 1mm MLPD-8
θJA = 36.3°C/W
Marking Information
Marking for the 3 x 3mm MLPD 8ld Lead Package:
yyww = Datecode ( Example : 0952 )
xxxx = Semtech Lot No. ( Example : E901 )
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SC4212
Thermal Information
Absolute Maximum Ratings
Thermal Resistance, Junction to Ambient (1) (°C/W) . . 36.3
VIN to GND (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +7
Thermal Resistance, Junction to Case (°C/W) . . . . . . . . 3.77
EN, FB, VOUT (V) . . . . . . . . . . . . . . . . . . . . . -0.3 to VIN +0.3
Operation Ambient Temperature Range (°C) . . -40 to +85
(2)
ESD Rating (kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5
Operation Junction Temperature Range (°C) . -40 to +125
Storage Temperature (°C) . . . . . . . . . . . . . . . . . . . -65 to +150
Recommended Operating Conditions
Peak IR Reflow Temperature (10s to 30s). . . . . . . . . . +260
Supply Input Voltage (V) . . . . . . . . . . . . . . . . . . . 1.5 to 6.0
Output Current Range . . . . . . . . . . . . . . . . . . . . . 8mA to 1A
Junction Temperature (°C) . . . . . . . . . . . . . . . . . -40 to +125
Exceeding the above specifications may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the
Electrical Characteristics section is not recommended.
NOTES:
(1)Calculated from package in still air, mounted to 3 x 4.5 (in), 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.
(2)Tested according to JEDEC standard JESD22-A114-B.
Electrical Characteristics
Unless specified otherwise: FB = VOUT, EN = VIN =, 1.5V to 6V, IOUT = 8mA to 1A,
TA = +25°C for Typ, -40 to +85 °C for Min and Max, TJ < 125°C.
Parameter
Symbol
Conditions
Min
Typ
Max
Units
6
V
VIN = 3.3V, IOUT = 0A
3
mA
VIN = 6V, EN = 0V
15
μA
Input Supply
Input Supply Voltage
Quiescent Current
VIN
IQ
1.5
Output
Output Voltage(1)
VOUT
VIN = 3.3V, IOUT = 10mA, TA = 25°C
-2%
1.5V < VIN < 6V, IOUT = 10mA
-3%
VOUT
+2%
V
+3%
Line Regulation(1)
REG(LINE)
IOUT = 10mA
0.20
0.40
%/V
Load Regulation(1)
REG(LOAD)
IOUT = 10mA to1A
0.50
1.50
%/A
Minimum Load Current(3)
IOUT
VIN = VOUT + 0.5V
8
mA
Current Limit
ICL
1.10
IOUT = 500mA, TA = 25°C
Dropout Voltage(1)(2)
VDO
1.5
100
IOUT = 500mA
IOUT = 1A, TA = 25°C
IOUT = 1A
A
250
300
mV
200
400
500
3
SC4212
Electrical Characteristics (continued)
Parameter
Symbol
Conditions
Min
VIN = 3.3V, FB = VOUT , IOUT = 10mA, TA = 25°C
0.495
Typ
Max
Units
0.505
V
Feedback
Reference Voltage(1)
Feedback Pin Current
0.500
VREF
0.490
0.510
IFB
FB = VREF
80
200
nA
IEN
EN = 0V, VIN = 3.3V
1.5
10.0
μA
VIH
VIN = 3.3V
VIL
VIN = 3.3V
Enable
Enable Input High Current
1.6
Enable Input Threshold
V
0.5
Over Temperature Protection
High Trip Level
Hysteresis
TOT
160
°C
TOT_HYS
10
°C
Notes:
(1) Low duty cycle pulse testing with Kelvin connections required.
(2) VDO = VIN - VOUT when VOUT decreases by 1.5% of its nominal output voltage when VIN = VOUT + 0.8V.
(3) Required to guarantee stable regulation. Voltage set resistors R1 and R2 can be utilized to meet this requirement.
4
SC4212
Typical Characteristics
Stability Curve, COUT = 100μF
Stability Curve, COUT = 10μF
IOUT (A)
IOUT (A)
Typical Dropout Voltage at VIN = 1.5 V
Typical Dropout Voltage at VIN = 5.0 V
450
350
400
TA = 125°C
250
300
Dropout Voltage (mV)
Dropout Voltage (mV)
300
TA = 125°C
350
TA = 25°C
250
200
TA = -40°C
150
100
50
TA = 25°C
200
150
TA = -40°C
100
50
0
0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
0.0
1.0
0.1
0.2
0.3
0.5
0.6
0.7
0.8
0.9
1.0
Reference Voltage vs. Junction Temperature
Reference Voltage vs. Junction Temperature
506
505
VIN = 1.5V
VIN = 5.5V
504
505
503
Reference Voltage (mV)
504
Reference Voltage (mV)
0.4
IOUT (A)
IOUT (A)
503
502
501
500
499
502
501
500
499
498
497
496
498
495
-40
0
25
Tj (ºC)
85
125
-40
0
25
85
125
TJ (ºC)
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SC4212
Pin Descriptions
Pin #
Pin Name
1,4,5
NC
No connect.
2
EN
Enable Input. Pulling this pin below 0.5V turns the regulator off, reducing the quiescent current to a fraction of its operating value. The device will be enabled if this pin is left open. Connect to VIN if the enable
feature is not being used.
3
VIN
Input voltage pin. For regulation at full load, the input to this pin must between ( VOUT + 0.5V ) and 6V.
Minimum VIN = 1.5V . A large bulk capacitance should be placed close to this pin to ensure that the input
supply does not sag below 1.5V. Also a minimum of 4.7μF ceramic capacitor should be placed directly at
this pin.
6
VOUT
7
Pin Function
This pin is the power output of this device. A minimum 10μF capacitor should be placed directly at this
pin.
When this pin is connected to the VOUT pin , the output voltage will be set to 0.5V . If external feedback
resistors are used , the output voltage will be determined by the resistor ratio (See Application Circuits on
page1):
0.5 ⋅ (R 1 + R 2 )
VOUT =
FB
⋅ Volts
R2
R1: The resistor connected from VOUT to FB.
R2: The resistor connected from FB to GND.
8
GND
Reference ground. The GND pin and the thermal pad must be connected together at the IC.
T
Thermal Pad
Thermal pad for heatsinking purposes. Not connected internally. Connect to ground plane using multiple
vias.
Block Diagram
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-
SC4212
Applications Information
Introduction
The SC4212 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 real estate. Additional features
include an enable pin to allow for a very low power consumption standby mode, and a fully adjustable output.
Component Selection
Input capacitor: A large bulk capacitance of ≥ 10 μF
should be placed close to the input supply pin of the
SC4212 to ensure that VIN does not sag below 1.5V. Also
a minimum 4.7μF ceramic capacitor is recommended
to be placed directly next to the VIN pin. This allows
for the device being some distance fromany bulk capacitance on the rail. Additionally, input droop due to
load transients is reduced, improving load transient
response. Additional capacitance may be added if required by the application.
Output capacitor: A minimum bulk capacitance of ≥
10μF, along with a 0.1μF ceramic decoupling capacitor
is recommended. Increasing the bulk capacitance will
improve the overall transient response.The use of multiple lower value ceramic capacitors in parallel to achieve
the desired bulk capacitance will not cause stability
issues. Although designed for use with ceramic output
capacitors, the SC4212 is extremely tolerant of output
capacitor ESR values and thus will also work comfortably
with tantalum output capacitors.
Noise immunity: In very electrically noisy environments,
it is recommended that 0.1 μF ceramic capacitors be
placed from VIN to GND and VOUT to GND as close to the
device pins as possible.
where an input voltage of < 1.9V is required. For applications with input voltages higher than 1.9V, the EN pin
could be left open or connected to VIN.
Thermal Considerations
The power dissipation in the SC4212 is approximately
equal to the product of the output current and the
input to output voltage differential:
PO = (VIN - VOUT ) x IOUT
The absolute worst-case dissipation is given by:
PO(MAX)=VIN(MAX)-VOUT(MIN))xIOUT(MAX)+VIN(MAX)xIQt(MAX)
For a typical scenario, VIN = 3.3V ± 5%, VOUT = 2.8V and
IOUT = 1A, therefore:
VIN(MAX) = 3.465V,
VOUT(MIN) = 2.744V and
IQ(MAX) = 3mA
Thus PD(MAX) = 0.731W.
Using this figure, and assuming TA(MAX) = 70°C, we can
calculate the maximum thermal impedance allowable
to maintain TJ ≤ 125°C:
§ TJ(MAX) − TA(MAX) · § 125°C − 85°C ·
¸=¨
R TH(J − A)(MAX) = ¨
= 76 °C
W
¨
¸ © 0.722W ¸¹
P
O(MAX)
©
¹
This should be achievable with the 3mm x 3mm MLPD-8
package using PCB copper area to aid in conducting the
heat away, such as one square inch of copper connected
to the ground pins of the device. Internal ground/power
planes and air flow will also assist in removing heat. For
higher ambient tempertures it may be necessary to use
additional copper area.
External voltage selection resistors: The use of 1%
resistors is recommended.
Enable: Pulling the EN pin below 0.5V turns the regulator off, reducing the quiescent current to a fraction of its
operating value. A pull up resistor up to 400kΩ should be
connected from the EN pin to the VIN pin in application
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SC4212
Outline Drawing — 3mm x 3mm MLPD-8
Land Pattern — 3mm x 3mm MLPD-8
K
Y
H
(C)
DIM
G
X
Z
DIMENSIONS
MILLIMETERS
INCHES
C
G
H
K
P
X
Y
Z
(.116)
.087
.067
.102
.026
.016
.030
.146
(2.95)
2.20
1.70
2.58
0.65
0.40
0.75
3.70
P
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
3.
THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD
SHALL BE CONNECTED TO A SYSTEM GROUND PLANE.
FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR
FUNCTIONAL PERFORMANCE OF THE DEVICE.
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SC4212
© Semtech 2011
All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner.
The information presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice. No liability will be accepted by the publisher for any consequence of its
use. Publication thereof does not convey nor imply any license under patent or other industrial or intellectual property
rights. Semtech assumes no responsibility or liability whatsoever for any failure or unexpected operation resulting from
misuse, neglect improper installation, repair or improper handling or unusual physical or electrical stress including, but
not limited to, exposure to parameters beyond the specified maximum ratings or operation outside the specified range.
SEMTECH PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN LIFESUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF SEMTECH PRODUCTS
IN SUCH APPLICATIONS IS UNDERSTOOD TO BE UNDERTAKEN SOLELY AT THE CUSTOMER’S OWN RISK. Should a customer
purchase or use Semtech products for any such unauthorized application, the customer shall indemnify and hold Semtech and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs damages and
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Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805) 498-2111 Fax: (805) 498-3804
www.semtech.com
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