Sample &
Buy
Product
Folder
Support &
Community
Tools &
Software
Technical
Documents
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
TPS22908 3.6-V, 1-A, 28-mΩ On-Resistance Load Switch with Controlled Rise Time
1 Features
2 Applications
•
•
•
•
•
•
•
•
•
•
•
•
•
1
•
•
•
•
•
•
Integrated P-Channel Load Switch
Input Voltage: 1 V to 3.6 V
1 A Maximum Continuous Switch Current
On-Resistance (Typical Values)
– RON = 28 mΩ at VIN = 3.6 V
– RON = 33 mΩ at VIN = 2.5 V
– RON = 42 mΩ at VIN = 1.8 V
– RON = 70 mΩ at VIN = 1.2 V
Maximum Quiescent Current = 1 µA
Maximum Shutdown Current = 1 µA
Low Control Input Thresholds Enable Use of 1.2V, 1.8-V, 2.5-V, and 3.3-V Logic
Controlled Slew Rate to Avoid Inrush Currents
– tR = 105 µs at VIN = 3.6V
Four Terminal Wafer-Chip-Scale Package
(WCSP)
– Nominal Dimensions - See Addendum for
Details
– 0.9 mm × 0.9 mm, 0.5-mm Pitch, 0.6-mm
Height
Quick Output Discharge (QOD)
Battery Powered Equipment
Portable Industrial Equipment
Portable Medical Equipment
Portable Media Players
Point of Sale Terminal
GPS Devices
Digital Cameras
Portable Instrumentation
Smartphones and Tablets
3 Description
The TPS22908 is a small, low RON load switch with
controlled turn on. The device contains a P-channel
MOSFET that operates over an input voltage range of
1 V to 3.6 V. The switch is controlled by an on/off
input (ON), which is capable of interfacing directly
with low-voltage control signals.
The TPS22908 is available in a space-saving 4terminal WCSP with 0.5 mm pitch (YZT). The device
is characterized for operation over the free-air
temperature range of –40°C to 85°C.
Device Information(1)
PART NUMBER
TPS22908
PACKAGE
BODY SIZE (NOM)
DSBGA (4)
0.9mm x 0.9mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Typical Application
Power
Supply
VOUT
VIN
ON
CIN
CL
ON
RL
OFF
TPS22908
GND
GND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
9
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Device Options.......................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
3
4
7.1
7.2
7.3
7.4
7.5
7.6
7.7
4
4
4
4
5
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Switching Characteristics ..........................................
Typical Characteristics ..............................................
Parameter Measurement Information ................ 11
Detailed Description ............................................ 12
9.1 Overview ................................................................. 12
9.2 Functional Block Diagram ....................................... 12
9.3 Feature Description................................................. 12
9.4 Device Functional Modes........................................ 12
10 Application and Implementation........................ 13
10.1 Application Information.......................................... 13
10.2 Typical Application ............................................... 13
11 Power Supply Recommendations ..................... 15
12 Layout................................................................... 15
12.1 Layout Guidelines ................................................. 15
12.2 Layout Example .................................................... 16
12.3 Thermal Considerations ........................................ 16
13 Device and Documentation Support ................. 17
13.1 Trademarks ........................................................... 17
13.2 Electrostatic Discharge Caution ............................ 17
13.3 Glossary ................................................................ 17
14 Mechanical, Packaging, and Orderable
Information ........................................................... 17
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision B (May 2013) to Revision C
•
Page
Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device Functional
Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device
and Documentation Support section, and Mechanical, Packaging, and Orderable Information section .............................. 1
Changes from Revision A (August 2012) to Revision B
Page
•
Updated FEATURES. ............................................................................................................................................................. 1
•
Added Layout graphic........................................................................................................................................................... 16
2
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
5 Device Options
FEATURE
VALUE
Device
TPS22908
RON (Typical) VIN = 3.6 V
28 mΩ
Rise Time (Typical) VIN = 3.6 V
105 µs
Quick Output Discharge (1)
Yes
Maximum Current
1A
Enable
(1)
Active high
This feature discharges the output of the switch to ground through an 80-Ω resistor, preventing the
output from floating.
6 Pin Configuration and Functions
YZT PACKAGE
4-PIN DSBGA
B
B
A
A
2
1
Laser Marking View
1 2
Bump View
Pin Functions
PIN
I/O
DESCRIPTION
NO.
NAME
A1
VOUT
O
Switch Output
A2
VIN
I
Switch input, bypass capacitor recommended for minimizing VIN dip. See Application Information.
B1
GND
—
B2
ON
I
Ground
Switch control input, active high. Do not leave floating.
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
3
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
www.ti.com
7 Specifications
7.1 Absolute Maximum Ratings
Over operating free-air temperature range (unless otherwise noted) (1)
MIN
MAX
UNIT (2)
VIN
Supply voltage
–0.3
4
V
VOUT
Output voltage
–0.3
(VIN + 0.3)
V
VON
Input voltage
–0.3
4
V
Maximum Continuous Switch Current for VIN ≥ 1.2 V
IMAX
1
A
Maximum Continuous Switch Current at VIN = 1 V
0.6
TJ
Maximum junction temperature (3)
125
°C
TLEAD
Maximum lead temperature (10-s soldering time)
300
°C
TSTG
Storage temperature
150
°C
(1)
(2)
(3)
–65
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltage values are with respect to network ground terminal.
In applications where high power dissipation and/or poor package thermal resistance is present, the maximum ambient temperature may
have to be derated. Maximum ambient temperature [TA(max)] is dependent on the maximum operating junction temperature [TJ(max)],
the maximum power dissipation of the device in the application [PD(max)], and the junction-to-ambient thermal resistance of the
part/package in the application (RθJA), as given by the following equation: TA(max) = TJ(max) – (RθJA × PD(max))
7.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±2000
Charged-device model (CDM), per JEDEC specification JESD22C101 (2)
±1000
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
7.3 Recommended Operating Conditions
MIN
MAX
VIN
Input voltage
1
3.6
V
VON
ON voltage
0
3.6
V
VOUT
Output voltage
0
VIN
V
VIH
High-level input voltage, ON
0.85
3.6
V
VIL
Low-level input voltage, ON
0
0.4
V
TA
Operating free-air temperature range
-40
85
CIN
Input capacitor
1 (1)
(1)
UNIT
°C
µF
Refer to application section.
7.4 Thermal Information
TPS22908
THERMAL METRIC (1)
YZT (DSBGA)
UNIT
4 PINS
RθJA
Junction-to-ambient thermal resistance
RθJC(top)
Junction-to-case (top) thermal resistance
RθJB
Junction-to-board thermal resistance
33
ψJT
Junction-to-top characterization parameter
9.1
ψJB
Junction-to-board characterization parameter
33
(1)
4
188
2
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
7.5 Electrical Characteristics
Unless otherwise noted the specification applies over the operating ambient temp –40°C ≤ TA ≤ 85°C. Typical values are for
VIN = 3.6 V, and TA = 25°C unless otherwise noted.
PARAMETER
TEST CONDITIONS
TA
MIN
TYP
MAX
UNIT
POWER SUPPLIES AND CURRENTS
IIN
Quiescent current
IOUT = 0 mA, VIN = VON
Full
0.19
1
µA
IIN(OFF)
OFF-state supply current
VON = 0 V, VOUT = Open
Full
0.12
1
µA
IIN(LEAK)
OFF-state supply current
VON = 0 V, VOUT = 0 V
Full
0.12
1
µA
ION
ON pin input leakage current
VON = 1.1 V to 3.6 V
Full
0.01
0.1
µA
25°C
28.2
32.1
RESISTANCE AND SWITCH CHARACTERISTICS
VIN = 3.6 V
VIN = 2.5 V
RON
ON-state resistance
IOUT = –200 mA
VIN = 1.8 V
VIN = 1.2 V
VIN = 1.0 V
RPD
Output pulldown resistance
VIN = 3.3 V, VON = 0 V, IOUT = 30 mA
Full
34.9
25°C
33.1
37.5
Full
40.6
25°C
41.5
50.3
Full
54.0
25°C
69.7
87.3
Full
91.2
25°C
112
155
Full
156
25°C
80
100
mΩ
mΩ
mΩ
mΩ
mΩ
Ω
7.6 Switching Characteristics
PARAMETER
TEST CONDITION
TPS22908
MIN
TYP
MAX
UNIT
VIN = 3.6 V, TA = 25°C (unless otherwise noted)
tON
Turn-ON time
RL = 10 Ω, CL = 0.1 µF
tOFF
Turn-OFF time
RL = 10 Ω, CL = 0.1 µF
5
tR
VOUT Rise time
RL = 10 Ω, CL = 0.1 µF
105
tF
VOUT Fall time
RL = 10 Ω, CL = 0.1 µF
2
493
110
µs
VIN = 1.0 V, TA = 25°C (unless otherwise noted)
tON
Turn-ON time
RL = 10 Ω, CL = 0.1 µF
tOFF
Turn-OFF time
RL = 10 Ω, CL = 0.1 µF
7
tR
VOUT Rise time
RL = 10 Ω, CL = 0.1 µF
442
tF
VOUT Fall time
RL = 10 Ω, CL = 0.1 µF
2
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
µs
5
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
www.ti.com
7.7 Typical Characteristics
7.7.1 Typical DC Characteristics
0.35
0.25
25C
−40C
85C
25C
−40C
85C
0.3
0.2
VON = GND, VOUT = 0V
IIN_LEAK (µA)
0.25
IIN (µA)
0.15
0.1
0.2
0.15
0.1
0.05
0.05
VOUT = Open, VIN = VON
0
1
1.5
2
2.5
VIN (V)
3
3.5
0
4
1
1.5
2
2.5
VIN (V)
3
3.5
4
G003
G004
Figure 1. VIN vs. Quiescent Current (IIN)
Figure 2. VIN vs. IIN(LEAK)
120
0.35
25C
−40C
85C
0.3
100
VON = GND, VOUT = Open
0.25
Ron (mOhm)
IIN_OFF (µA)
80
0.2
0.15
60
40
0.1
20
0.05
IOUT = −200mA
0
1
1.5
2
2.5
VIN (V)
3
3.5
0
−40
4
−15
Vin = 1V
Vin = 1.2V
Vin = 1.8V
10
35
Temperature (°C)
Vin = 2.5V
Vin = 3.3V
Vin = 3.6V
60
85
G005
G002
Figure 3. VIN vs. IIN(OFF)
Figure 4. Temperature vs. RON
120
140
25C
−40C
85C
100
Temp = 25C
VIN = 1.0V
VIN = 1.2V
VIN = 1.8V
VIN = 2.5V
VIN = 3.6V
130
120
110
100
Ron (mOhm)
RON (mΩ)
80
60
40
90
80
70
60
50
20
40
30
IOUT = −200mA
0
0.5
1
1.5
2
2.5
Vin (V)
3
3.5
4
20
0
0.1
0.2
0.3
0.4 0.5 0.6
Load Current (A)
0.7
0.8
0.9
G001
Figure 5. VIN vs. RON
6
1
G001
Figure 6. RON vs. Load Current
(Various VIN at TA = 25°C)
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
Typical DC Characteristics (continued)
120
100
25C
−40C
85C
25C
−40C
85C
110
90
100
RPD (Ω)
RPD (Ω)
80
70
90
80
70
60
60
VIN = 3.6V
IOUT = 1mA
50
0
5
10
15
IOUT (mA)
20
25
50
30
1
1.5
2
2.5
Vin (V)
3
3.5
4
G006
G007
Figure 8. VIN vs. RPD
4
4
3
3
2
2
VOUT (V)
VOUT (V)
Figure 7. IOUT vs. RPD
1
1
0
0
Vin = 1V
Vin = 1.2V
Vin = 1.8V
25C, Falling Edge
−1
0
0.6
1.2
1.8
VON (V)
Vin = 2.5V
Vin = 3.3V
Vin = 3.6V
2.4
3
Vin = 1V
Vin = 1.2V
Vin = 1.8V
25C, Rising Edge
−1
3.6
0
0.6
1.2
1.8
VON (V)
Vin = 2.5V
Vin = 3.3V
Vin = 3.6V
2.4
3
3.6
G009
G008
Figure 9. VON Threshold vs. VOUT
(ON pin Voltage Decreasing)
Figure 10. VON Threshold vs. VOUT
(ON Pin Voltage Increasing)
7.7.2 Typical Switching Characteristics
120
600
115
550
110
tR (µs)
tR (µs)
500
105
450
100
400
95
VIN = 3.6V, CL = 0.1uF, RL = 10Ohm
90
−40
−15
10
35
Temperature (°C)
VIN = 1V, CL = 0.1uF, RL = 10Ohm
60
350
−40
85
G013
Figure 11. Rise Time vs. Temperature (VIN = 3.6 V)
−15
10
35
Temperature (°C)
60
85
G018
Figure 12. Rise Time vs. Temperature (VIN = 1 V)
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
7
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
www.ti.com
Typical Switching Characteristics (continued)
2.3
2.3
2.1
2.1
tF (µs)
2.5
tF (µs)
2.5
1.9
1.9
1.7
1.7
VIN = 3.6V, CL = 0.1uF, RL = 10Ohm
1.5
−40
−15
10
35
Temperature (°C)
VIN = 1V, CL = 0.1uF, RL = 10Ohm
60
1.5
−40
85
−15
10
35
Temperature (°C)
60
G024
Figure 13. Fall Time vs. Temperature (VIN = 3.6 V)
G019
Figure 14. Fall Time vs. Temperature (VIN = 1 V)
130
600
120
550
tON (µs)
650
tON (µs)
140
110
500
100
450
VIN = 3.6V, CL = 0.1uF, RL = 10Ohm
90
−40
−15
10
35
Temperature (°C)
VIN = 1V, CL = 0.1uF, RL = 10Ohm
60
400
−40
85
−15
10
35
Temperature (°C)
60
G001
Figure 15. Turnon Time vs. Temperature (VIN = 3.6 V)
G006
8
16
6
12
tOFF (µs)
20
tOFF (µs)
85
Figure 16. Turnon Time vs. Temperature (VIN = 1 V)
10
4
8
2
4
VIN = 3.6V, CL = 0.1uF, RL = 10Ohm
0
−40
−15
10
35
Temperature (°C)
VIN = 1V, CL = 0.1uF, RL = 10Ohm
60
0
−40
85
G012
Figure 17. Turnoff Time vs. Temperature (VIN = 3.6 V)
8
85
−15
10
35
Temperature (°C)
60
85
G007
Figure 18. Turnoff Time vs. Temperature (VIN = 1 V)
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
Typical Switching Characteristics (continued)
800
800
CL = 0.1uF, RL = 10Ohm, VON=1.8V
25C
−40C
85C
CL = 1uF, RL = 10Ohm, VON=1.8V
600
600
500
500
400
400
300
300
200
200
100
100
0
1
1.5
2
2.5
Vin (V)
3
25C
−40C
85C
700
tR (µs)
tR (µs)
700
0
3.5
G025
1
1.5
2
2.5
Vin (V)
3
3.5
G026
Figure 19. Rise Time vs. VIN (CL = 0.1 µF)
Figure 20. Rise Time vs. VIN (CL = 1 µF)
Figure 21. Turn on Response Time (VIN = 3.6 V, CIN = 10
µF, CL = 1 µF, RL = 10 Ω)
Figure 22. Turn on Response Time (VIN = 1 V, CIN = 10 µF,
CL = 1 µF, RL = 10 Ω)
Figure 23. Turn on Response Time (VIN = 3.6 V, CIN = 1 µF,
CL = 0.1 µF, RL = 10 Ω)
Figure 24. Turn on Response Time (VIN = 1 V, CIN = 1 µF,
CL = 0.1 µF, RL = 10 Ω)
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
9
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
www.ti.com
Typical Switching Characteristics (continued)
10
Figure 25. Turn off Response Time (VIN = 3.6 V, CIN = 10
µF, CL = 1 µF, RL = 10 Ω)
Figure 26. Turn off Response Time (VIN = 1 V, CIN = 10 µF,
CL = 1 µF, RL = 10 Ω)
Figure 27. Turn off Response Time (VIN = 3.6 V, CIN = 1 µF,
CL = 0.1 µF, RL = 10 Ω)
Figure 28. Turn off Response Time (VIN = 1 V, CIN = 1 µF,
CL = 0.1 µF, RL = 10 Ω)
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
8 Parameter Measurement Information
VIN
VOUT
CIN = 1µF
ON
+
-
(A)
CL
ON
RL
OFF
GND
TPS22908
GND
GND
TEST CIRCUIT
VON
50%
50%
tOFF
tON
VOUT
50%
50%
tf
tr
90%
VOUT
10%
90%
10%
t ON/t OFF WAVEFORMS
A.
Rise and fall times of the control signal is 100 ns.
Figure 29. Test Circuit and tON/tOFF Waveforms
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
11
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
www.ti.com
9 Detailed Description
9.1 Overview
The TPS22908 is a single channel, 1 A load switch in a small, space-saving DSBGA-4 package. This device
implements a P-channel MOSFET to provide a low on-resistance for a low voltage drop across the device. A
controlled rise time is used in applications to limit the inrush current.
9.2 Functional Block Diagram
VIN
Control
Logic
ON
VOUT
GND
9.3 Feature Description
9.3.1 ON/OFF Control
The ON pin controls the state of the switch. Activating ON continuously holds the switch in the on state. ON is
active high and has a low threshold making it capable of interfacing with low-voltage signals. The ON pin is
compatible with standard GPIO logic threshold, and it can be used with any microcontroller with 1.2-V, 1.8-V, 2.5V or 3.3-V GPIOs.
9.3.2 Quick Output Discharge
The TPS22908 includes the Quick Output Discharge (QOD) feature. When the switch is disabled, a discharge
resistance with a typical value of 80 Ω is connected between the output and ground. This resistance pulls down
the output and prevents it from floating when the device is disabled.
9.4 Device Functional Modes
Table 1. Functional Table
12
ON
VIN to VOUT
L
OFF
ON
H
ON
OFF
Submit Documentation Feedback
VOUT to GND
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
10 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
10.1 Application Information
10.1.1 Input Capacitor (Optional)
To limit the voltage drop on the input supply caused by transient inrush currents when the switch turns on into a
discharged load capacitor, a capacitor can be placed between VIN and GND. A 1 µF ceramic capacitor, CIN,
placed close to the pins, is usually sufficient. Higher values of CIN can be used to further reduce the voltage drop
during high-current application. When switching heavy loads, it is recommended to have an input capacitor about
10 times higher than the output capacitor to avoid excessive voltage drop.
10.1.2 Output Capacitor (Optional)
Due to the integrated body diode of the PMOS switch, a CIN greater than CL is highly recommended. A CL
greater than CIN can cause VOUT to exceed VIN when the system supply is removed. This could result in current
flow through the body diode from VOUT to VIN. A CIN to CL ratio of at least 10 to 1 is recommended for minimizing
VIN dip caused by inrush currents during startup; however, a 10 to 1 ratio for capacitance is not required for
proper functionality of the device. A ratio smaller than 10 to 1 (such as 1 to 1) could cause slightly more VIN dip
at turn on due to inrush currents.
10.2 Typical Application
Power
Supply
VOUT
VIN
ON
CIN
CL
ON
RL
OFF
TPS22908
GND
GND
Figure 30. Typical Application Schematic
10.2.1 Design Requirements
The following input parameters will be used in these design examples.
Table 2. Design Parameters
DESIGN PARAMETER
EXAMPLE VALUE
VIN
1.8 V
CL
10 µF
Load current
500 mA
Ambient Temperature
25 °C
Maximum inrush current
200 mA
10.2.2 Detailed Design Procedure
10.2.2.1 Managing Inrush Current
When the switch is enabled, the output capacitors must be charged up from 0 V to the set value (1.8 V in this
example). This charge arrives in the form of inrush current. Inrush current can be calculated using Equation 1:
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
13
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
IINRUSH = CL ´
www.ti.com
dVOUT
dt
where:
•
•
•
CL = Output capacitance
dVOUT = Output voltage
dt = Rise time
(1)
The TPS22908 offers a controlled rise time for minimizing inrush current. This device can be selected based
upon the minimum acceptable rise time which can be calculated using the design requirements and the inrush
current equation. An output capacitance of 4.7 µF will be used since the amount of inrush current increases with
output capacitance:
200 mA = 10 µF × 1.8V / dt
dt = 90 µs
(2)
To ensure an inrush current of less than 200 mA, a device with a rise time greater than 90 µs must be used. The
TPS22908 has a typical rise time of 160 µs at 1.8 V which meets the above design requirements.
10.2.2.2 VIN to VOUT Voltage Drop
The voltage drop from VIN to VOUT is determined by the ON-resistance of the device and the load current. RON
can be found in Electrical Characteristics and is dependent on temperature. When the value of RON is found, the
following equation can be used to calculate the voltage drop across the device:
ΔV = ILOAD × RON
where:
•
•
•
ΔV = Voltage drop across the device
ILOAD = Load current
RON = ON-resistance of the device
(3)
At VIN = 1.8 V, the TPS22908 has an RON value of 42 mΩ. Using this value and the defined load current, the
above equation can be evaluated:
ΔV = 500 mA × 42 mΩ
ΔV = 21 mV
(4)
Therefore, the voltage drop across the device will be 21 mV.
14
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
10.2.3 Application Curve
Figure 31. Inrush Current with a Load Capacitance of 10µF (VIN = 1.8 V, TA = 25°C)
11 Power Supply Recommendations
The device is designed to operate with a VIN range of 1 V to 3.6 V. This supply must be well regulated and
placed as close to the device terminals as possible. It must also be able to withstand all transient and load
currents, using a recommended input capacitance of 1 µF if necessary. If the supply is located more than a few
inches from the device terminals, additional bulk capacitance may be required in addition to the ceramic bypass
capacitors. If additional bulk capacitance is required, an electrolytic, tantalum, or ceramic capacitor of 10 µF may
be sufficient.
12 Layout
12.1 Layout Guidelines
For best performance, VIN, VOUT, and GND traces should be as short and wide as possible to help minimize
the parasitic electrical effects. To be most effective, the input and output capacitors should be placed close to the
device to minimize the effects that parasitic trace inductances may have on normal operation.
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
15
TPS22908
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
www.ti.com
12.2 Layout Example
Figure 32. Layout Example
12.3 Thermal Considerations
For higher reliability, the maximum IC junction temperature, TJ(max), should be restricted to 125˚C under normal
operating conditions. Junction temperature is directly proportional to power dissipation in the device and the two
are related by:
TJ = TA + RθJA × PD
where:
•
•
•
•
16
TJ = Junction temperature of the device
TA = Ambient temperature
PD = Power dissipation inside the device
RθJA = Junction to ambient thermal resistance. See Thermal Information for more information. This parameter
is highly dependent on board layout.
(5)
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
TPS22908
www.ti.com
SLVSBI7C – JULY 2012 – REVISED APRIL 2015
13 Device and Documentation Support
13.1 Trademarks
All trademarks are the property of their respective owners.
13.2 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
13.3 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
14 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
Submit Documentation Feedback
Copyright © 2012–2015, Texas Instruments Incorporated
Product Folder Links: TPS22908
17
PACKAGE OPTION ADDENDUM
www.ti.com
10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
TPS22908YZTR
ACTIVE
DSBGA
YZT
4
3000
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-40 to 85
AT
TPS22908YZTT
ACTIVE
DSBGA
YZT
4
250
RoHS & Green
SNAGCU
Level-1-260C-UNLIM
-40 to 85
(AT, ATF)
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
工商网监
湘ICP备2023018690号
