TPS65321-Q1 Datasheet, PDF (1/42 Pages) Texas Instruments – Step-Down Converter With Eco-mode and LDO Regulator

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TPS65321-Q1
SLVSCF0A – OCTOBER 2015 – REVISED DECEMBER 2015
TPS65321-Q1 36-V Step-Down Converter With Eco-mode™ and LDO Regulator
1 Features
•1 Qualified for Automotive Applications
• AEC-Q100 Qualified with the Following Results:
– Device Temperature Grade 1: –40°C to
+125°C Ambient Operating Temperature
– Device HBM ESD Classification Level 2
– Device CDM ESD Classification Level C4B
• One High-VIN Step-Down DC-DC Converter
– Input Range of 3.6-V to 36-V
– 250-mΩ High-Side MOSFET
– Maximum Load Current 3.2-A, Output
Adjustable 1.1-V to 20-V
– Adjustable Switch-Mode Frequency 100-kHz to
2.5-MHz
– Synchronizes to External Clock
– Maximum 140-μA Operating Quiescent
Current
– High Efficiency at Light Loads With Pulse-
Skipping Eco-mode™ Control Scheme
– Reset Output-Pin (Active Low, Open-Drain)
• One High-VIN Low-Dropout (LDO) Voltage
Regulator
– Input Range of 3-V to 36-V
– 280-mA Current Capability With Typical 35-µA
Operating Quiescent Current in No-Load
Condition
– Low-Dropout Voltage of 300-mV at
I_O = 200-mA (Typical)
• Overcurrent Protection for Both Regulators
• Overtemperature Protection
• 14-Pin HTSSOP Package With PowerPAD™
Integrated Circuit Package
Typical Application Schematic
VI = 3.6 to 36 V
Supply
VIN
BOOT
SW
1.1 to 20 V, 3.2 A
EN1
RT/CLK
SS
VI = 3 to 36 V _{VIN_LDO}
Supply
GND
EN2
Buck
Regulator
Control
LDO
Regulator
Control
FB1
COMP
nRST
LDO_OUT
FB2
1.1 to 5.5 V, 280 mA
PowerPAD
TPS65321-Q1
1
2 Applications
• Automotive Infotainment and Cluster
• Advanced Driver Assistance System (ADAS)
• Automotive Telematics, eCall
• 12-V and 24-V Industrial and Commercial Low
Power System
3 Description
The TPS65321-Q1 device is a combination of a high-
VIN DC-DC step-down converter, referred to as the
buck regulator, with an adjustable switch-mode
frequency from 100-kHz to 2.5-MHz, and a high-VIN
280-mA low-dropout (LDO) regulator. The input range
is 3.6-V to 36-V for the buck regulator, and 3-V to 36-
V for the LDO regulator. The buck regulator has an
integrated high-side MOSFET and an active-low,
open-drain power-good output-pin (nRST). The LDO
regulator also has an integrated MOSFET and
features a low-input supply current of 35-μA typical in
no-load condition. The low-voltage tracking feature
enables the TPS65321-Q1 device to track the input
supply during cold-crank conditions.
The buck regulator provides a flexible design to fit
system needs. The external loop compensation circuit
allows for optimization of the converter response for
the appropriate operating conditions. A low-ripple
pulse-skip mode reduces the no-load input-supply
current to maximum 140-μA.
The device has built-in protection features such as
soft start, current-limit, thermal sensing, and
shutdown because of excessive power dissipation.
Furthermore, the device has an internal undervoltage-
lockout (UVLO) function that turns off the device
when the supply voltage is too low.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS65321-Q1
HTSSOP (14)
5.00 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Buck Efficiency Versus Output Current
100
90
80
70
60
50
40
30
20
10
fs = 300 kHz
fs = 2 MHz
0
0
1
2
3
4
Load Current (A)
D001
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.