TPS59124 Datasheet, PDF (1/25 Pages) Texas Instruments – Dual Synchronous Step-Down Controller for Low-Voltage Power Rails in Embedded Computing Systems

TPS59124
www.ti.com
SLUSA58 – JULY 2010
Dual Synchronous Step-Down Controller
for Low-Voltage Power Rails in Embedded Computing Systems
FEATURES
1
•2 High Efficiency, Low-Power Consumption,
Shutdowns to <1 mA
• Fixed Frequency Emulated On-Time Control,
Frequency Selectable From Three Options
• D-CAP™ Mode Enables Fast Transient
Response
• Auto-Skip Mode
• Less Than 1% Initial Reference Accuracy
• Low Output Ripple
• Wide Input Voltage Range: 3 V to 28 V
• Output Voltage Range: 0.76 V to 5.5 V
• Low-Side R_DS(on) Loss-less Current Sensing
• Adaptive Gate Drivers With Integrated Boost
Diode
• Internal 1.2-ms Voltage-Servo Soft Start
• Power-Good Signals for Each Channel With
Delay Timer
• Output Discharge During Disable, Fault
APPLICATIONS
• I/O and Low Voltage System Bus in Embedded
Computing Systems
DESCRIPTION
The TPS59124 is a dual, adaptive on-time D-CAP™
mode synchronous buck controller. This device
enables system designers to cost effectively complete
the suite of embedded computer power bus
regulators with the absolute lowest external
component count and lowest standby consumption.
The fixed-frequency emulated adaptive on-time
control supports seamless operation between PWM
mode at heavy load condition and reduced frequency
operation at light load for high-efficiency down to
milliampere range. The main control loop for the
TPS59124 uses the D-CAP mode that optimized for
low-ESR output capacitors such as POSCAP or
SP-CAP promises fast transient response with no
external compensation. Simple and separate power
good signals for each channel allow flexibility of
power sequencing. The device provides convenient
and efficient operation with supply input voltages
(V5IN, V5FILT) ranging from 4.5 V to 5.5 V,
conversion voltages (drain voltage for the
synchronous high-side MOSFET) from 3 V to 28 V
and output voltages from 0.76 V to 5.5 V.
The TPS59124 is available in 24-pin QFN package
specified from –40°C to 85°C ambient temperature
range.
Input Voltage
3 V to 28 V
C9
22 µF
R5
R2
R4 _{75 kΩ}
73.2 kΩ
SGND
75
kΩ
R1
28.7 kΩ
654321
VO2
1.5 V/10 A
SGND PGND
Power
Good2
C6
10 µF
Q3
IRF7821
L2
1 µH
EN2
C5
0.1 µF
7 PGOOD2
8 EN2
9 VBST2
10 DRVH2
PGOOD1 24
TM
PowerPAD
EN1 23
Power
Good1
EN1
TPS59124RGE
VBST1 22
C2
0.1 µF
DRVH1 21
Q1
IRF7821
C4
2 x 330 µF
V5IN
4.5 V to 5.5 V
Q4
IRF8113
11 LL2
12 ^DRVL2
LL1 20
DRVL1 ₁₉
Q2
IRF8113
PGND
13 14 15 16 17 18
R6
6.8 kΩ
R7 ^R3
3.3Ω ^6.8
kΩ
C7
4.7 μF
C8
1 μF
PGND
PGND
SGND
C3
L1 ^{10 µF}
1 µH
VO1
1.05 V/10 A
C1
2 x 330 µF
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
D-CAP, PowerPAD are trademarks of Texas Instruments.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated