SC728 [SEMTECH]
2A Low Vin, Very Low Ron Load Switch;
| 型号： | SC728 |
| 厂家： | 
SEMTECH CORPORATION |
| 描述： | 2A Low Vin, Very Low Ron Load Switch |
| 文件： | 总15页 (文件大小：2148K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SC728/SC729
2A Low Vin, Very Low Ron
Load Switch
POWER MANAGEMENT
Features
Description
The SC728/SC729 is a low input voltage, very low Ron
load switch designed for use in battery powered applica-
tions. Very low quiescent current of less than 2µA, and a
low shutdown current of less than 1µA (SC728) reduces
power loss during Standby and Off states. A logic level
Enable allows low voltage on/off control down to 1.1V.
Input Voltage Range – 1.1V to 3.6V
2A Continuous Output Current
Ultra-Low Ron – 36mΩ
Automatic Output Discharge Circuit
Fast Turn-on Option With No Output Discharge
Circuit – SC728
Extended Soft Start Option With Automatic Out-
put Discharge Circuit – SC729
The SC728 provides a quick turn on time, while the SC729
provides a longer soft start to limit inrush current. The
SC729 also features an automatic discharge circuit which
discharges the output when the part is disabled.
Low Quiescent Current – 0.81µA(Typ.)
Low Shutdown Current < 1µA – SC728
1.1V Logic Level Enable Compatible With CMOS/GPIO
Control
The SC728/SC729 is offered in an ultra-small 4-bump
0.76mm × 0.76mm Chip Scale Package (CSP) which
enables very small board area implementations. The
SC728/SC729 has an operating ambient temperature
range of -40°C to +85°C.
Hardened ESD Protection 3kV
Package: CSP – 0.76mm × 0.76mm, 0.4mm Pitch
SC724/SC725 offers an alternative bump connection
pattern to SC728/SC729. Please go to Semtech.com
website for details.
Applications
Smart Phones
Tablet PCs
GPS Devices
Battery Powered Equipment
Other Portable Device
Automatic
Device
SC728
SC729
Package
CSP
Rising Time
3µs(Typ.)
Discharge
No
CSP
Yes
140µs(Typ.)
Typical Application Circuit
SUPPLY
LOAD
VIN
EN
VOUT
1µF
1µF
SC728 / SC729
GND
ENABLE
Rev. 2.2
1
© 2015 Semtech Corporation
SC728/SC729
Pin Configuration
Ordering Information
Device
Package
TO P VIEW
(BUM PS O N THE BO TTO M )
SC728CSTRT
SC729CSTRT
SC728EVB
CSP 0.76mm×0.76mm 4-bump
CSP 0.76mm×0.76mm 4-bump
Evaluation Board
Evaluation Board
A1
B1
A2
B2
SC729EVB
Notes:
(1) Available in tape and reel only. A reel contains 5,000 devices.
(2) Lead-free packaging only. Device is WEEE and RoHS compliant,
and halogen free.
CSP 0.76x0.76, 4 Bump
Pin Descriptions
Pin
Name
Pin #
Pin Function
A2
B2
VIN
EN
Input Voltage.
Enable input. A 5.5MΩ internal resistor is connected from this pin to GND. Drive HIGH to turn on the switch;
drive LOW to turn off the switch. When the EN pin is floated, the switch is OFF.
A1
B1
VOUT
GND
Output Voltage.
Ground.
2
SC728/SC729
Marking Information(SC729)
Marking Information(SC728)
Marking for the 0.76 x 0.76 mm CSP 4 Lead Package :
O = Pin 1 ID
Marking for the 0.76 x 0.76 mm CSP 4 Lead Package :
O = Pin 1 ID
nn = Part No. Code (Example: AV) - Reference Part No.
nn = Part No. Code (Example: AY) - Reference Part No.
3
SC728/SC729
Absolute Maximum Ratings
Recommended Operating Conditions
VIN to GND (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +4.3
EN to GND (V). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +4.3
OUT to GND (V) . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3 to +VVIN
ESD Protection Level(1) (kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Ambient Temperature Range (°C) . . . . . . . . . -40 < TA < +85
VVIN (V). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 to 3.6
Maximum Output Current (A) . . . . . . . . . . . . . . . . . . . . . . . . 2
Thermal Information
Thermal Resistance, Junction to Ambient(2) (°C/W) . . . 160
Maximum Junction Temperature (°C) . . . . . . . . . . . . . . +125
Storage Temperature Range (°C). . . . . . . . . . . . -65 to +150
Peak IR Reflow Temperature (10s to 30s) (°C) . . . . . . . +260
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) Tested according to JEDEC standard JS-001-2012.
(2) 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.
Electrical Characteristics
Unless noted otherwise, TA = 25°C for typical, -40°C < TA = TJ < 85°C for min and max. VVIN = 1.8V, CIN = 1μF, COUT = 1μF, VEN = VVIN
.
Parameter
Symbol
Conditions
Min
Typ
24
Max
47
Units
mΩ
mΩ
mΩ
mΩ
mΩ
µA
VVIN =3.6V, IOUT = 200mA, VEN =1.5V
VVIN =2.5V, IOUT = 200mA, VEN =1.5V
VVIN =1.8V, IOUT = 200mA, VEN =1.5V
VVIN =1.5V, IOUT = 200mA, VEN =1.5V
VVIN =1.2V, IOUT = 200mA, VEN =1.0V
VVIN = VEN = 3.6V, VOUT =open
29
On Resistance (Ron)
RON
36
43
57
Quiescent Current (1)
Enable
IQ
0.81
2
EN Input High Threshold
EN Input Low Threshold
EN Input Pull-Down Resistance
SC728
VEN-IH
VEN-IL
REN
1.1
V
V
0.3
5.5
MΩ
VEN =0V, VOUT = open
1
µA
µA
Shutdown Current
ISD
VEN =0V, VOUT = open, TA = 25°C
0.2
4
SC728/SC729
Electrical Characteristics (continued)
Parameter
Symbol
Conditions
Min
Typ
11
Max
Units
µs
VVIN =1.8V, IOUT = 200mA, VEN =1.5V, COUT=1µF
VVIN =3.6V, IOUT = 200mA, VEN =1.5V, COUT=1µF
VVIN =1.8V, IOUT = 200mA, VEN =1.5V, COUT=1µF
VVIN =3.6V, IOUT = 200mA, VEN =1.5V, COUT=1µF
Turn-on Delay Time
TDT
2.8
8.5
3
µs
µs
Rising Time
SC729
TRT
µs
VEN =0V, VOUT = open
8
µA
µA
µs
µs
µs
µs
Ω
Shutdown Current
ISD
VEN =0V, VOUT = open, TA = 25°C
0.6
VVIN =1.8V, IOUT = 200mA, VEN =1.5V, COUT=1µF
VVIN =3.6V, IOUT = 200mA, VEN =1.5V, COUT=1µF
VVIN =1.8V, IOUT = 200mA, VEN =1.5V, COUT=1µF
VVIN =3.6V, IOUT = 200mA, VEN =1.5V, COUT=1µF
VVIN =1.8V
240
110
250
140
250
Turn-on Delay Time
Rising Time
TDT
TRT
Output Pull-Down Resistance
Notes:
RPD
(1) IQ current includes EN pull-down current.
Timing Diagram
Turn-on
Delay
Turn-off
Delay
V
EN
VOUT
90%
10%
Rising
Time
Falling
Time
(Turn on time)=(Turn-on Delay)+(Rising Time)
5
SC728/SC729
Typical Characteristics (SC728)
Shut Down by VIN
Start Up by VIN
3.6Vin,1.8Ω
3.6Vin,1.8Ω
VIN
1V/div.
VOUT
1V/div.
VIN
1V/div.
VOUT
IIN
1A/div.
1V/div.
IOUT
1A/div.
IIN
1A/div.
IOUT
1A/div.
Time (5ms/div)
Time (5ms/div)
Start Up by EN
Start Up by EN
1.8Vin, 0A
3.6Vin,0A
VIN
1V/div.
VIN
0.5V/div.
VOUT
VOUT
1V/div.
0.5V/div.
IIN
IIN
1A/div.
1A/div.
EN
EN
2V/div.
2V/div.
Time (10µs/div)
Time (10µs/div)
Shut Down by EN
3.6Vin, 18Ω
VIN
1V/div.
VOUT
1V/div.
IOUT
0.2A/div.
EN
2V/div.
Time (20µs/div)
6
SC728/SC729
Typical Characteristics (SC728), Cont.
On Resistance vs. Temperature
On Resistance vs. Temperature
Iout=200mA
Iout=2A
1.2V
1.2V
1.5V
1.8V
3.6V
2.5V
3.6V
Temperature (°C)
Temperature (°C)
Shut Down Current vs. Temperature
Quiescent Current vs. Temperature
3.6V
3.6V
1.8V
1.1V
1.8V
1.1V
Temperature (°C)
Temperature (°C)
EN Input Pull-Down Resistance vs. Temperature
Turn-on Delay Time vs. Temperature
Vin=1.8V
1.1V
1.8V
3.6V
Ķ
Temperature (°C)
Temperature (°C)
7
SC728/SC729
Typical Characteristics (SC729)
Shut Down by VIN
Start Up by VIN
3.6Vin,1.8Ω
3.6Vin,1.8Ω
VIN
1V/div.
VOUT
1V/div.
VIN
1V/div.
VOUT
1V/div.
IOUT
IOUT
1A/div.
IIN
1A/div.
1A/div.
IIN
1A/div.
Time (5ms/div)
Time (5ms/div)
Start Up by EN
Start Up by EN
1.8Vin, 0.9Ω
3.6Vin,1.8Ω
VIN
0.5V/div.
VIN
1V/div.
VOUT
0.5V/div.
VOUT
1V/div.
IOUT
1A/div.
EN
IOUT
1A/div.
EN
2V/div.
2V/div.
Time (0.1ms/div)
Time (0.2ms/div)
Shut Down by EN
3.6Vin, 18Ω
EN High Threshold vs. Temperature
VIN
1V/div.
VOUT
1V/div.
1.8V
IOUT
0.2A/div.
1.1V
EN
2V/div.
Time (5µs/div)
Temperature (°C)
8
SC728/SC729
Typical Characteristics (SC729), Cont.
Turn-off Delay vs. Temperature
Shut Down Current vs. Temperature
3.6V
3.6V
1.8V
1
1.1V
Temperature (°C)
Temperature (°C)
Turn-on Delay vs. Temperature
Falling Time vs. Temperature
1.8V
3.6V
1.8V
3.6V
Temperature (°C)
Temperature (°C)
Output Pull-Down Resistance vs. Temperature
Vin=1.8V
Rising Time vs. Temperature
1.8V
3.6V
Temperature (°C)
Temperature (°C)
9
SC728/SC729
Block Diagram
SC728
VOUT
VIN (1.1V to 3.6V)
C1
C2
EN
Slew Rate
Control
ILoad
(Up to 2A)
SC728
GND
SC729
VOUT
VIN (1.1V to 3.6V)
C1
C2
Slew Rate
Control
EN
ILoad
(Up to 2A)
SC729
GND
10
SC728/SC729
Application Information
Operation
Output Capacitor
A 1µF ceramic capacitor is normally used at the VOUT pin
to suppress output noise and provide smooth voltage to
the load. If a larger output capacitance value is used, the
input inrush current should be considered because the
power-on transient is also dependent on the output
capacitor value. Note that SC729 has longer Turn-on Delay
Time and Rising Time than SC728. If a larger output
capacitor is used, SC729 could significantly improve input
inrush current during power-on process.
The SC728/SC729 is an integrated high-side PMOS load
switch that is designed to support up to 2A continuous
output current and operate from an input voltage from
1.1V to 3.6V. The internal PMOS pass element has a very
low ON resistance of 36mΩ (typical) at VIN = 1.8V. The
SC728/SC729 also provides ultra-low shutdown and qui-
escent current for extended battery life during applica-
tion off and standby states.
SC729 provides longer Turn-on Delay Time and Rising
Time, which can help reduce inrush current and voltage
drop on the input supply rail during power on.
Board Layout Considerations
Fig. 1 shows a typical application circuit with PCB induc-
tance on the circuit board. An important objective of the
layout is to minimize the PCB inductance by reducing the
length and increasing the width of the traces. The input
capacitor C1 and output capacitor C2 need to be placed
close to the SC728/SC729. To analyze the stray inductance,
Fig. 1 shows three current loops during the opening or
closing of the load switch. The magnitude of the voltage
ringing at VIN or VOUT pin is related to the PCB stray
inductance and the placement of the capacitors. It is
important to keep the voltage ringing below the maximum
voltage rating of the SC728/SC729.
SC728 provides shorter Turn-on Delay and Rising Time for
applications where immediate response is required.
Output Voltage Pull-down
The SC729 also includes an automatic output discharge
function. It employs a 250Ω (typical) discharge path to
ground when the EN pin is disabled.
Enable
The EN pin controls the ON/OFF states of the load switch.
Pulling the EN pin HIGH turns on the load switch. Pulling
the EN pin LOW turns off the load switch. The EN pin
incorporates a 5.5MΩ (typical) pull-down resistor, so that
when the EN pin is floating the SC728/SC279 is disabled.
LPCB
LPCB
LPCB
LPCB
VIN
VOUT
GND
+
-
C2
1uF
C1
1uF
SC728/SC729
RL
I
OUT
I
IN
Input Capacitor
I
SW
In order to reduce the effects of voltage drop, noise, and
bounce at the VIN pin, a filter/decoupling capacitor
between VIN to GND is recommended. A 1µF ceramic
capacitor is sufficient for most application conditions.
However, it should be noted that suppressing bounce at
input loop after EN is changed from HIGH to LOW can
require greater capacitor values depending on particular
designs. During certain shutdown conditions, as in the
case when input power supply is abruptly removed, the
input voltage may tend to drop faster than the output
voltage. In this event a reverse current, through the body
diode of internal PMOS FET, from VOUT to VIN can occur.
To limit this reverse current, the Cin value should be
selected greater than the Cout value.
L
PCB
Figure 1 - PCB Circuit with Equivalent Parasitic
Inductance
Evaluation Board Information
The Top Layer and Bottom Layer of a standard evaluation
board are shown in Fig. 2 and Fig. 3, respectively.
Both T1 and T2 test points are Kelvin connections which
can be used to minimize the measurement error of RON
To enable the part, a jumper can be used between VIN
and EN on J1. To disable the part, a jumper can be con-
nected between EN and GND on J1.
.
11
SC728/SC729
Top Layer
Figure 2
Bottom Layer
Figure 3
12
SC728/SC729
Outline Drawing — CSP 0.76mm X 0.76mm, 4 Lead
13
SC728/SC729
Land Pattern — CSP 0.76mm X 0.76mm, 4 Lead
14
SC728/SC729
© Semtech 2015
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accurate and reliable and may be changed without notice. No liability will be accepted by the publisher for any conse-
quence of its use. Publication thereof does not convey nor imply any license under patent or other industrial or intellec-
tual 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.
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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
15
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