SLVSCF0B October   2015  – June 2017 TPS65321-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Buck Regulator
        1. 7.3.1.1  Fixed-Frequency PWM Control
        2. 7.3.1.2  Slope Compensation Output
        3. 7.3.1.3  Pulse-Skip Eco-mode™ Control Scheme
        4. 7.3.1.4  Dropout Mode Operation and Bootstrap Voltage (BOOT)
        5. 7.3.1.5  Error Amplifier
        6. 7.3.1.6  Voltage Reference
        7. 7.3.1.7  Adjusting the Output Voltage
        8. 7.3.1.8  Soft-Start and Tracking Pin (SS/TR)
        9. 7.3.1.9  Reset Output, nRST
        10. 7.3.1.10 Overload-Recovery Circuit
        11. 7.3.1.11 Constant Switching Frequency and Timing Resistor (RT/CLK Pin)
        12. 7.3.1.12 Overcurrent Protection and Frequency Shift
        13. 7.3.1.13 Selecting the Switching Frequency
        14. 7.3.1.14 How to Interface to RT/CLK Pin
        15. 7.3.1.15 Overvoltage Transient Protection
        16. 7.3.1.16 Small-Signal Model for Loop Response
        17. 7.3.1.17 Simple Small-Signal Model for Peak-Current Mode Control
        18. 7.3.1.18 Small-Signal Model for Frequency Compensation
      2. 7.3.2 LDO Regulator
        1. 7.3.2.1 Charge-Pump Operation
        2. 7.3.2.2 Low-Voltage Tracking
        3. 7.3.2.3 Adjusting the Output Voltage
      3. 7.3.3 Thermal Shutdown
      4. 7.3.4 Enable and Undervoltage Lockout
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Soft-Start Discharge
      2. 8.1.2 Passive Discharge Through a Resistor in Parallel With the SS Capacitor
      3. 8.1.3 Active Discharge Through A NPN Transistor
    2. 8.2 Typical Applications
      1. 8.2.1 2.2-MHzSwitching Frequency, 9-V to 16-V Input, 3.3-V Output Buck Regulator, 5-V Output LDO Regulator
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Switching Frequency Selection for the Buck Regulator
          2. 8.2.1.2.2  Output Inductor Selection for the Buck Regulator
          3. 8.2.1.2.3  Output Capacitor Selection for the Buck Regulator
          4. 8.2.1.2.4  Catch Diode Selection for the Buck Regulator
          5. 8.2.1.2.5  Input Capacitor Selection for the Buck Regulator
          6. 8.2.1.2.6  Soft-Start Capacitor Selection for the Buck Regulator
          7. 8.2.1.2.7  Bootstrap Capacitor Selection for the Buck Regulator
          8. 8.2.1.2.8  Output Voltage and Feedback Resistor Selection for the Buck Regulator
          9. 8.2.1.2.9  Frequency Compensation Selection for the Buck Regulator
          10. 8.2.1.2.10 LDO Regulator
          11. 8.2.1.2.11 Power Dissipation
            1. 8.2.1.2.11.1 Power Dissipation Losses of the Buck Regulator
          12. 8.2.1.2.12 Power Dissipation Losses of the LDO Regulator
          13. 8.2.1.2.13 Total Device Power Dissipation Losses and Junction Temperature
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Design Example With 500-kHz Switching Frequency
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
          1. 8.2.2.2.1 Selecting the Switching Frequency
          2. 8.2.2.2.2 Output Inductor Selection
          3. 8.2.2.2.3 Output Capacitor
          4. 8.2.2.2.4 Compensation
        3. 8.2.2.3 Application Curve
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • PWP|14
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
Supply inputs VIN –0.3 40 V
VIN_LDO –0.3 40
Control EN1, EN2 –0.3 40 V
EN1-VIN, EN2-VIN 1
Buck converter FB1 –0.3 3.6 V
SW –0.3
–2 V for 30 ns 		40
BOOT –0.3 46
BOOT-SW 8
COMP –0.3 3.6
SS –0.3 3.6
RT/CLK, SS –0.3 3.6
nRST –0.3 7
LDO regulator LDO_OUT –0.3 7 V
FB2 –0.3 7
Operating ambient temperature, TA 125 °C
Operating junction temperature range, TJ –40 150
Storage temperature, Tstg –55 165 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

6.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per AEC Q100-002(1) ±2000 V
Charged-device model (CDM), per AEC Q100-011 All pins ±500
Corner pins (1, 7, 8, and 14) ±750
(1) AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
Supply inputs VIN 3.6 36 V
VIN_LDO 3 36
Buck regulator BOOT1 3.6 42 V
SW1 –1 36
VFB1 0 0.8
SS 0 3
COMP 0 3
RT/CLK 0 3
nRST 0 5.25
LDO regulator LDO_OUT 1.1 5.5 V
VFB2 0 0.8
Control EN1 0 36 V
EN2 0 36
Temperature Operating junction temperature range, TJ –40 150 °C

6.4 Thermal Information

THERMAL METRIC(1) TPS65321-Q1 UNIT
PWP (HTSSOP)
14 PINS
RθJA Junction-to-ambient thermal resistance 41.0 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 33.1 °C/W
RθJB Junction-to-board thermal resistance 25.4 °C/W
ψJT Junction-to-top characterization parameter 1.6 °C/W
ψJB Junction-to-board characterization parameter 25.1 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 2.7 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

6.5 Electrical Characteristics

VI = 6 V to 27 V, EN1 = EN2 = VI, over-operating free-air temperature range TA = –40°C to 125°C and maximum operating junction temperature TJ = –150°C, unless otherwise noted. VI is the voltage on the battery-supply terminals, VIN and VIN_LDO.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
VIN (INPUT POWER SUPPLY)
Operating input voltage Normal mode, after initial start-up 3.6 12 36 V
Shutdown supply current V(EN1) = V(EN2) = 0 V, 25°C 2 7 μA
Initial start-up voltage 6 36 V
ENABLE AND UVLO (EN1 AND EN2 TERMINALS)
Enable low level 0.7 V
Enable high level 2.5 V
V(VIN)(f) Internal UVLO falling threshold Ramp V(VIN) down until output turns OFF 1.8 2.6 3 V
V(VIN)(r) Internal UVLO rising threshold Ramp V(VIN) up until output turns ON 2.2 2.8 3.2 V
BUCK REGULATOR
I(Qon) Operating: non-switching supply Measured at the VIN terminal
V(FB1) = 0.83 V, V(VIN) = 12 V, 25°C 		110 140 μA
Output capacitance ESR = 0.001 Ω to 0.1 Ω, large output capacitance may be required for load transient 10 μF
V(ref1) Voltage reference for FB1 terminal Buck regulator output: 1.1 V to 20 V.
Buck regulator in Continuous Conducting Mode without Pulse-Skipping 		0.788 0.8 0.812 V
DC output voltage accuracy Includes voltage references, DC load and line regulation, process and temperature –2% 2%
DC(LDR) DC Load regulation, ΔVOUT / VOUT IOUT = 0 to IOUTmax 0.5%
T(LDSR) Transient load step response V(VIN) = 12V, IOUT = 200 mA to 3A, TR = TF = 1 µs, Buck Output Voltage = 5V, ƒS = 2 MHz 5%
BUCK REGULATOR: HIGH-SIDE MOSFET
r(DS(on) HS FET) On-resistance V(VIN) = 12 V, V(SW) = 6 V 127 250 mΩ
tonmin Minimum on-time ƒS = 2.5 MHz 115 ns
BUCK REGULATOR: CURRENT-LIMIT
Current-limit threshold V(VIN) = 12 V, TJ = 25°C 4 6 A
BUCK REGULATOR: TIMING RESISTOR AND EXTERNAL CLOCK (RT/CLK TERMINAL)
ƒS Switching-frequency range using RT mode 100 2500 kHz
Switching frequency Under fixed-frequency PWM mode, with 200 kΩ connected between terminal RT/CLK and GND 523 585 640 kHz
Switching-frequency range using CLK mode 300 2200 kHz
Minimum CLK input pulse width Measures at CLK input = 2.2 MHz 30 ns
RT/CLK High threshold 1.9 2.2 V
RT/CLK Low threshold 0.5 0.7 V
RT/CLK Falling edge to SW rising edge delay Measured at 500 kHz with external clock connected to RT/CLK terminal 60 ns
PLL Lock-in time Measured at 500 kHz 100 μs
LDO REGULATOR
ΔVO(ΔVI) Line regulation V(VIN_LDO) = 6 V to 30 V, I(LDO_OUT) = 10 mA, V(LDO_OUT) = 3.3 V 20 mV
ΔVO(ΔIL) Load regulation I(LDO_OUT) = 10 mA to 200 mA, V(VIN_LDO) = 12 V, V(LDO_OUT) = 3.3 V 35 mV
VDROPOUT Dropout voltage
(V(VIN_LDO) – V(LDO_OUT))		 I(LDO_OUT) = 200 mA 300 450 mV
I(LDO_OUT) Output current V(LDO_OUT) in regulation, V(VIN) ≥ 4V 280 mA
VI(VIN_LDO) Operating input voltage on VIN_LDO terminal V(LDO_OUT) in regulation 3 36 V
V(ref2) Voltage reference FB2 terminal V(LDO_OUT) = 1.1 V to 5.5 V 0.788 0.8 0.812 V
ICL(LDO_OUT) Output current-limit V(LDO_OUT) = 0 V (the LDO_OUT terminal is shorted to ground) 280 1000 mA
IQ(LDO) Quiescent current V(VIN) = 12 V; Measured at VIN pin
V(EN1) = 0 V, V(EN2) = 5 V,
I(LDO_OUT) = 0.01 mA to 0.75 mA 		35 50 μA
PSRR Power supply ripple rejection V(VIN_LDO)(rip) = 0.5 VPP, I(LDO_OUT) = 200 mA,
frequency (ƒ) = 100 Hz,
V(LDO_OUT) = 5 V and V(LDO_OUT) = 3.3 V		 60 dB
V(VIN_LDO)(rip) = 0.5 VPP, I(LDO_OUT) = 200 mA,
ƒ = 150 kHz,
V(LDO_OUT) = 5 V and V(LDO_OUT) = 3.3 V		 30 dB
C(LDO_OUT) Output capacitor ESR = 0.001 Ω to 100 mΩ, large output capacitance may be required for load transient
V(LDO_OUT) ≥ 3.3 V 		1 40 μF
C(LDO_OUT) Output capacitor ESR = 0.001 Ω to 100 mΩ, large output capacitance may be required for load transient
1.2 V ≤ V(LDO_OUT) < 3.3 V 		20 40 μF
BUCK REGULATOR: RESET (nRST TERMINAL)
RESET threshold V(FB1) decreasing 85% 90% 95%
VOL Output low nRST terminal asserted low due to falling V(FB1), < 1-mA sinking current into nRST terminal 0 0.045 0.4 V
Filter time Delay before asserting nRST low 7 14 21 μs
OVER TEMPERATURE PROTECTION
TSD Thermal-shutdown trip point 175 ºC
Thys Hysteresis 10 ºC

6.6 Typical Characteristics

TPS65321-Q1 C002_slvscf0.gif
ƒS = 2 MHz 3.6 V ≤ V(VIN) ≤ 6 V
Figure 1. Maximum-Possible Buck-Regulator Output Voltage
TPS65321-Q1 C003_slvscf0.png
V(VIN) = 12 V TJ = 25°C
Figure 3. Buck-Regulator Switching Frequency vs RT_CLK Resistance
TPS65321-Q1 C008_slvscf0.gif
V(VIN_LDO) = 5 V V(LDO_OUT) = 3.3 V
Figure 5. LDO-Regulator Load Regulation
TPS65321-Q1 C010_slvscf0.gif
I(LDO_OUT) = 100 mA V(VIN_LDO) = 12 V
Figure 7. LDO-Regulator Feedback-Voltage Reference (V(FB2)) vs Junction Temperature
TPS65321-Q1 C004_slvscf0.png
V(VIN) = 12 V
Figure 2. Buck-Regulator Switching Frequency vs V(FB1) Feedback Voltage
TPS65321-Q1 C007_slvscf0.gif
No Load V(VIN) = 12 V
Figure 4. Buck-Regulator Feedback-Voltage Reference (V(FB1)) vs Junction Temperature
TPS65321-Q1 C009_slvscf0.gif
V(LDO_OUT) = 5 V
Figure 6. LDO-Regulator Dropout Voltage vs Load Current