SC724/SC725

SC724/SC725
2A Low Vin, Very Low Ron
Load Switch
POWER MANAGEMENT
Features






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Description
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 – SC724
 Extended Soft Start Option With Automatic Output Discharge Circuit – SC725
Low Quiescent Current – 0.81µA(Typ.)
Low Shutdown Current < 1µA – SC724
1.1V Logic Level Enable Compatible With CMOS/GPIO
Control
Hardened ESD Protection 3kV
Package: CSP – 0.76mm × 0.76mm, 0.4mm Pitch
Applications
The SC724/SC725 is a low input voltage, very low Ron
load switch designed for use in battery powered applications. Very low quiescent current of less than 2µA, and a
low shutdown current of less than 1µA (SC724) reduces
power loss during Standby and Off states. A logic level
Enable allows low voltage on/off control down to 1.1V.
The SC724 provides a quick turn on time, while the SC725
provides a longer soft start to limit inrush current. The
SC725 also features an automatic discharge circuit which
discharges the output when the part is disabled.
The SC724/SC725 is offered in an ultra-small 4-bump
0.76mm × 0.76mm Chip Scale Package (CSP) which
enables very small board area implementations. The
SC724/SC725 has an operating ambient temperature
range of -40°C to +85°C.
SC724/SC725 offers an alternative bump connection
pattern to SC724/SC725. Please go to Semtech.com
website for details.
Smart Phones
Tablet PCs
 GPS Devices
 Battery Powered Equipment
 Other Portable Device


Automatic
Rising Time
Discharge
Device
Package
SC724
CSP
No
3µs(Typ.)
SC725
CSP
Yes
140µs(Typ.)
Typical Application Circuit
SUPPLY
VIN
1µF
ENABLE
Rev. 2.0
1µF
SC724 / SC725
EN
LOAD
VOUT
GND
© 2014 Semtech Corporation
SC724/SC725
Pin Configuration
Ordering Information
T O P V IE W
(B U M P S O N T H E B O T T O M )
A1
A2
B1
B2
Device
Package
SC724CSTRT
CSP 0.76mm×0.76mm 4-bump
SC725CSTRT
CSP 0.76mm×0.76mm 4-bump
SC724EVB
Evaluation Board
SC725EVB
Evaluation Board
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 #
Pin
Name
A1
VIN
Input Voltage.
B1
EN
Enable input. A 5.0MΩ 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.
A2
VOUT
Output Voltage.
B2
GND
Ground.
Pin Function
SC724/SC725
Marking Information(SC724)
Marking Information(SC725)
Marking for the 0.76 x 0.76 mm CSP 4 Lead Package :
Marking for the 0.76 x 0.76 mm CSP 4 Lead Package :
O = Pin 1 ID
O = Pin 1 ID
nn = Part No. Code (Example: AR) - Reference Part No.
nn = Part No. Code (Example: AT) - Reference Part No.
SC724/SC725
Absolute Maximum Ratings
Recommended Operating Conditions
VIN to GND (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +4.3
Ambient Temperature Range (°C). . . . . . . . . -40 < TA < +85
EN to GND (V). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +4.3
VVIN (V). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 to 3.6
OUT to GND (V) . . . . . . . . . . . . . . . . . . . . . . . . . .-0.3 to +VVIN
Maximum Output Current (A). . . . . . . . . . . . . . . . . . . . . . . . . 2
ESD Protection Level (kV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
(1)
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
On Resistance (Ron)
Quiescent Current (1)
Symbol
RON
IQ
Conditions
Min
Typ
Max
Units
VVIN =3.6V, IOUT = 200mA, V
�EN =1.5V
24
mΩ
VVIN =2.5V, IOUT = 200mA, V
�EN =1.5V
29
mΩ
VVIN =1.8V, IOUT = 200mA, V
�EN =1.5V
36
VVIN =1.5V, IOUT = 200mA, V
�EN =1.5V
43
mΩ
VVIN =1.2V, IOUT = 200mA, V
�EN =1.0V
57
mΩ
VVIN = VEN = 3.6V, VOUT = open
0.81
47
2
mΩ
µA
Enable
EN Input High Threshold
VEN-IH
EN Input Low Threshold
VEN-IL
EN Input Pull-Down Resistance
1.1
V
0.3
REN
5.0
V
MΩ
SC724
Shutdown Current
ISD
VEN =0V, VOUT = open
1
µA
VEN =0V, VOUT = open, TA = 25��
°C
0.2
µA
SC724/SC725
Electrical Characteristics (continued)
Parameter
Symbol
Turn-on Delay Time
TDT
Rising Time
TRT
Conditions
Min
Typ
Max
Units
VVIN =1.8V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
11
µs
VVIN =3.6V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
2.8
µs
VVIN =1.8V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
8.5
µs
VVIN =3.6V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
3
µs
SC725
Shutdown Current
ISD
Turn-on Delay Time
TDT
Rising Time
Output Pull-Down Resistance
TRT
VEN =0V, VOUT = open
8
µA
VEN =0V, VOUT = open, TA = 25��
°C
0.6
µA
VVIN =1.8V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
240
µs
VVIN =3.6V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
110
µs
VVIN =1.8V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
250
µs
VVIN =3.6V, IOUT = 200mA, V
�EN =1.5V, COUT=1µF
140
µs
VVIN =1.8V
220
Ω
RPD
Notes:
(1) IQ current includes EN pull-down current.
Timing Diagram
Turn-on
Delay
Turn-off
Delay
VEN
VOUT
90%
10%
Rising
Time
Falling
Time
(Turn on time)=(Turn-on Delay)+(Rising Time)
StartupbyEN
StartupbyEN
SC724/SC725
Testingcondition:VIN=3.6V,25Ԩ,
Testingcondition:VIN=3.6V,25Ԩ,
Shutdown by VIN
Iout=2A,C1=C2=1uF,CRMode
Iout=2A,C1=C2=1uF,CRMode
Testingcondition:VIN=1.8V,25Ԩ,
Testingcondition:VIN=1.8V,25Ԩ,
Start up by VIN
Iout=2A,C1=C2=1uF,CRMode
Iout=2A,C1=C2=1uF,CRMode
VIN
VOUT
Testing condition: VIN=3.6V,
Iout=0.5A, C2=1uF, 25Ԩ,
Typical Characteristics (SC724)
3.6Vin,1.8Ω
Start Up by VIN
VIN VIN
VIN
VOUT
VOUT
IIN
VOUT
IIN
3.6Vin,1.8Ω
VIN
1V/div.
VOUT
1V/div.
Shut Down by VIN
Testing condition: VIN=3.6V,
Iout=0.5A, C2=1uF, CR mode, 25ɗ
IIN
VIN
VOUT
VIN
1V/div.
VOUT
1V/div.
EN
Iin
EN
IOUT
IIN
1A/div.
T5(Vin)
T6(Vout)
IIN
1A/div.
EN
IOUT
1A/div.
Iout
Iin
IOUT
IOUT
1A/div.
Time (5ms/div)
Time (5ms/div)
Testingcondition:VIN=1.8V,25Ԩ,
Testingcondition:VIN=1.8V,25Ԩ,
Iout=2A,C1=C2=1uF,CRMode
Start Up by EN
Iout=2A,C1=C2=1uF,CRMode
1.8Vin, 0A
Testingcondition:VIN=3.6V,25Ԩ,
Testingcondition:VIN=3.6V,25Ԩ,
Iout=2A,C1=C2=1uF,CRMode
Start Up by EN
Iout=2A,C1=C2=1uF,CRMode
3.6Vin,0A
VIN VIN
VIN
VOUT
VOUT1V/div.
VIN
VOUT
VIN
0.5V/div.
IIN
VOUT
0.5V/div.
IIN
IIN
1A/div.
VOUT
1V/div.
IIN
IIN
1A/div.
EN
EN
2V/div.
Time (10µs/div)
3.6Vin, 18Ω
EN
EN
2V/div.
EN
Time (10µs/div)
Shut Down by EN
VIN
1V/div.
VOUT
1V/div.
IOUT
0.2A/div.
EN
2V/div.
Time (20µs/div)
SC724/SC725
RON@200mA
RON@2A
Typical Characteristics (SC724), Cont.
On Resistance vs. Temperature
Iout=200mA
Ĺı
Ĺı
1.2V
ķı
Ķı
1.5V
1.8V
ĵı
2.5V
Ĵı
3.6V
ijı
1.2V
ķı
Ķı
1.8V
ĵı
3.6V
Ĵı
ijı
Quiescent Current
IJı
Shutdown Current
IJı
Įĵı
ijĶ
ĹĶ
Temperature (°C)
Įĵı
ŕŦŮűŦųŢŵŶųŦĩɗĪ
ijĶ
ĹĶ
Temperature (°C)
ŕŦŮűŦųŢŵŶųŦĩɗĪ
Shut Down Current vs. Temperature
Quiescent Current vs. Temperature
ıįĴij
IJįı
ıįĺ
ıįijĹ
3.6V
Shut
Down Current (µA)
ŔũŶŵťŰŸůġńŶųųŦůŵĩŶłĪ
Quiescent
Current (µA)
ŒŶŪŦŴŤŦůŵġńŶųųŦůŵĩŶłĪ
On Resistance vs. Temperature
ĸı
On Resistance
(mΩ)
œŰůĩŮȟĪ
On Resistance
(mΩ)
œŰůĩŮȟĪ
ĸı
Iout=2A
ıįĹ
ıįĸ
ıįķ
ıįĶ
ıįĵ
ıįĴ
1.8V
ıįij
ıįIJ
Turn-on delay time
1.1V
ıįijı
ıįIJķ
3.6V
ıįIJij
ıįıĹ
1.8V
ıįıĵ
1.1V
ıįıı
ıįı
Įĵı
ıįijĵ
ijĶ
ĹĶ
Temperature (°C)
Įĵı
ijĶ
Temperature (°C)
ĹĶ
ŕŦŮűŦųŢŵŶųŦĩɗĪ
ŕŦŮűŦųŢŵŶųŦĩɗĪ
Turn-on Delay Time vs. Temperature
ŕŶųůĮŐůġŅŦŭŢźġŕŪŮŦĩŶŔĪ
Turn-on delay time (µs)
ķı
Ķı
1.1V
ĵı
Ĵı
ijı
1.8V
IJı
3.6V
ı
Įĵı
ijĶ
Temperature (°C)
ĹĶ
ŕŦŮűŦųŢŵŶųŦĩɗĪ
SC724/SC725
Typical Characteristics (SC725)
3.6Vin,1.8Ω
VIN
1V/div.
VOUT
1V/div.
IOUT
1A/div.
IIN
1A/div.
VIN
0.5V/div.
Start Up by VIN
3.6Vin,1.8Ω
Shut Down by VIN
VIN
1V/div.
VOUT
1V/div.
IOUT
1A/div.
IIN
1A/div.
Time (5ms/div)
Time (5ms/div)
1.8Vin, 0.9Ω
Start Up by EN
3.6Vin,1.8Ω
Start Up by EN
VIN
1V/div.
VOUT
0.5V/div.
VOUT
1V/div.
IOUT
1A/div.
EN
2V/div.
Time (0.2ms/div)
3.6Vin, 18Ω
IOUT
1A/div.
EN
2V/div.
Shut Down by EN
Time (0.1ms/div)
EN High Threshold vs. Temperature
IJııı
VIN
1V/div.
EN High
Threshold (mV)
œŰůĩŮȟĪ
ĺĶı
VOUT
1V/div.
IOUT
0.2A/div.
ĺıı
3.6V
ĹĶı
Ĺıı
ĸĶı
1.8V
ĸıı
ķĶı
ķıı
1.1V
ĶĶı
EN
2V/div.
Ķıı
Time (5µs/div)
Įĵı
ijĶ
Temperature (°C)
ĹĶ
ŕŦŮűŦųŢŵŶųŦĩɗĪ
SC724/SC725
Typical Characteristics (SC725), Cont.
Turn-off Delay vs. Temperature
Shut Down Current vs. Temperature
ijįĶ
IJĹ
3.6V
Turn Off Delay (µs)
ijįı
3.6V
IJįĶ
ņŏġőŶŭŭťŰŸůġœŦŴŪŴŵŢůŤŦĩŎȟĪ
ŔũŶŵťŰŸůġńŶųųŦůŵĩŶłĪ
Shut Down Current (µA)
IJķ
IJįı
1.8V
ıįĶ
1.1V
IJĵ
IJij
IJı
Ĺ
ķ
1.8V
ĵ
ij
ı
ıįı
Įĵı
ijĶ
Įĵı
ĹĶ
Temperature (°C)
Falling Time vs. Temperature
Ĺ
Ĵıı
ĸ
Falling Time (µs)
ĴĶı
ijĶı
1.8V
ņŏġőŶŭŭťŰŸůġœŦŴŪŴŵŢůŤŦĩŎȟĪ
ņŏġőŶŭŭťŰŸůġœŦŴŪŴŵŢůŤŦĩŎȟĪ
Turn On Delay (µs)
Turn-on Delay vs. Temperature
ijıı
IJĶı
3.6V
Ķı
ı
Įĵı
ĹĶ
ŕŦŮűŦųŢŵŶųŦĩɗĪ
ŕŦŮűŦųŢŵŶųŦĩɗĪ
IJıı
ijĶ
Temperature (°C)
ijĶ
ĹĶ
Temperature (°C)
ŕŦŮűŦųŢŵŶųŦĩɗĪ
1.8V
ķ
3.6V
Ķ
ĵ
Ĵ
ij
IJ
ı
Įĵı
ijĶ
Temperature (°C)
ĹĶ
ŕŦŮűŦųŢŵŶųŦĩɗĪ
Rising Time vs. Temperature
ĴĶı
ņŏġőŶŭŭťŰŸůġœŦŴŪŴŵŢůŤŦĩŎȟĪ
Rising Time (µs)
Ĵıı
ijĶı
1.8V
ijıı
IJĶı
3.6V
IJıı
Ķı
ı
Įĵı
ijĶ
ĹĶ
Temperature (°C)
ŕŦŮűŦųŢŵŶųŦĩɗĪ
SC724/SC725
Block Diagram
SC724
VOUT
VIN (1.1V to 3.6V)
C1
Slew Rate
Control
EN
C2
ILoad
(Up to 2A)
SC724
GND
SC725
VOUT
VIN (1.1V to 3.6V)
C1
Slew Rate
Control
EN
C2
ILoad
(Up to 2A)
SC725
GND
10
SC724/SC725
Application Information
Operation
Output Capacitor
The SC724/SC725 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
SC724/SC725 also provides ultra-low shutdown and quiescent current for extended battery life during application off and standby states.
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 SC725 has longer Turn-on Delay
Time and Rising Time than SC724. If a larger output
capacitor is used, SC725 could significantly improve input
inrush current during power-on process.
SC725 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.
SC724 provides shorter Turn-on Delay and Rising Time for
applications where immediate response is required.
Output Voltage Pull-down
The SC725 also includes an automatic output discharge
function. It employs a 220Ω (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 5.0MΩ (typical) pull-down resistor, so that
when the EN pin is floating the SC724/SC275 is disabled.
Board Layout Considerations
Fig. 1 shows a typical application circuit with PCB inductance 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 SC724/SC725. 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 SC724/SC725.
LPCB
LPCB
+
-
IIN
C1
1uF
VIN
VOUT
LPCB
LPCB
C2
1uF
SC724/SC725
IOUT
RL
GND
Input Capacitor
ISW
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.
LPCB
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 connected between EN and GND on J1.
11
SC724/SC725
Top Layer
DBN461!W!21/6!;!Xfe!Kbo!26!27;69;44!3125!.!)Voujumfe*
Figure 2
Bottom Layer
DBN461!W!21/6!;!Uiv!Kbo!27!21;68;69!3125!.!)Voujumfe*
Figure 3
12
SC724/SC725
Outline Drawing — CSP 0.76mm X 0.76mm, 4 Lead
13
SC724/SC725
Land Pattern — CSP 0.76mm X 0.76mm, 4 Lead
14
SC724/SC725
© Semtech 2014
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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