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Contents

README

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TPS65321AQPWPRQ1

Texas Instruments · Linear Voltage Regulators (LDO) · TSSOP-14-EP

TPS65321AQPWPRQ1 from Texas Instruments, in a TSSOP-14-EP. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 BOOT passive Bootstrap capacitor is required between BOOT and SW to supply the bias voltage for the integrated high-side MOSFET (abs max 46 V, BOOT-SW 8 V).
2 VIN power_in Input supply pin for the internal biasing and high-side MOSFET of the buck regulator, 3.6 V to 36 V input range (abs max 40 V).
3 VIN_LDO power_in Input supply pin for the LDO regulator, 3 V to 36 V input range (abs max 40 V).
4 LDO_OUT power_out LDO regulator output, 280 mA capability, adjustable 1.1 V to 5.5 V (abs max 7 V).
5 FB2 input Feedback pin of the LDO regulator; connect an external resistive divider between LDO_OUT, FB2 and GND to set the LDO output voltage.
6 nRST output Active-low open-drain reset output of the buck regulator; connect to an external bias voltage through a resistor, asserted high after the buck begins regulating.
7 EN2 input Enable input for the LDO regulator, high-voltage tolerant and internally pulled to ground; pull up externally to enable.
8 EN1 input Enable input for the buck regulator, high-voltage tolerant and internally pulled to ground; pull up externally to enable.
9 RT/CLK input Connect an external resistor to ground to program the buck switching frequency, or feed an external clock as the switching frequency reference.
10 SS input Connect an external capacitor to ground to set the soft-start time of the buck regulator.
11 FB1 input Feedback pin of the buck regulator; connect an external resistive divider from the buck output to GND to set the output voltage.
12 COMP output Error-amplifier output of the buck regulator and input to the output switch-current comparator; connect frequency-compensation components here.
13 GND power_in Ground pin.
14 SW output Source node of the internal high-side MOSFET of the buck regulator (abs max 40 V).
15 PowerPAD power_in Exposed thermal pad; electrically connect to ground and solder to the PCB ground plane for thermal performance.

Key specifications

Parameter Value
Manufacturer Texas Instruments
Package TSSOP-14-EP
Category Power Supply Chip
Pins 15

Electrical characteristics

Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).

Parameter Symbol Min Typ Max Unit Conditions Page
VIN supply input voltage VIN -0.3 40 V 4
VIN_LDO supply input voltage VIN_LDO -0.3 40 V 4
Control pins EN1, EN2 EN1, EN2 -0.3 40 V 4
Buck feedback pin FB1 FB1 -0.3 3.6 V 4
Buck switch node SW SW -0.3 40 V 4
Buck BOOT pin BOOT -0.3 46 V 4
Buck BOOT-SW voltage BOOT-SW 8 V 4
Buck error amplifier output COMP COMP -0.3 3.6 V 4
Buck soft-start pin SS SS -0.3 3.6 V 4
Buck RT/CLK pin RT/CLK -0.3 3.6 V 4
Reset output nRST nRST -0.3 7 V 4
LDO output LDO_OUT LDO_OUT -0.3 7 V 4
LDO feedback pin FB2 FB2 -0.3 7 V 4
Operating ambient temperature TA -40 125 °C 4
Operating junction temperature TJ -40 150 °C 4
Storage temperature Tstg -55 165 °C 4
Supply input VIN (recommended) VIN 3.6 36 V 5
Supply input VIN_LDO (recommended) VIN_LDO 3 36 V 5
Buck BOOT pin (recommended) BOOT 3.6 42 V 5
Buck switch node SW1 (recommended) SW1 -1 36 V 5
Buck feedback FB1 (recommended) FB1 0 0.8 V 5
Buck soft-start SS (recommended) SS 0 3 V 5
Buck COMP (recommended) COMP 0 3 V 5
Buck RT/CLK (recommended) RT/CLK 0 3 V 5
Reset output nRST (recommended) nRST 0 5.25 V 5
LDO output LDO_OUT (recommended) LDO_OUT 1.1 5.5 V 5
LDO feedback FB2 (recommended) FB2 0 0.8 V 5
Enable EN1 (recommended) EN1 0 36 V 5
Enable EN2 (recommended) EN2 0 36 V 5
Operating junction temperature range (recommended) TJ -40 150 °C 5
Operating input voltage 3.6 12 36 V Normal mode, after initial start-up 6
Shutdown supply current 2 7 μA V(EN1) = V(EN2) = 0 V, 25°C 6
Enable low level 0.7 V 6
Enable high level 2.5 V 6
Internal UVLO falling threshold V(VIN)(f) 1.8 2.6 3 V Ramp V(VIN) down until output turns OFF 6
Internal UVLO rising threshold V(VIN)(r) 2.2 2.8 3.2 V Ramp V(VIN) up until output turns ON 6
Operating non-switching supply current (buck) I(Qon) 110 140 μA Measured at the VIN pin, V(FB1) = 0.83 V, V(VIN) = 12 V, 25°C 6
Buck voltage reference for FB1 V(ref1) 0.788 0.8 0.812 V Buck regulator output: 1.1 V to 20 V. Buck regulator in Continuous Conducting Mode without Pulse-Skipping 6
DC output voltage accuracy -2 2 % Includes voltage references, DC load and line regulation, process and temperature 6
Buck high-side MOSFET on-resistance r(DS(on) HS FET) 127 250 mΩ V(VIN) = 12 V, V(SW) = 6 V 6
Buck current-limit threshold 4 6 A V(VIN) = 12 V, TJ = 25°C 6
Buck switching frequency range (RT mode) ƒS 100 2500 kHz Under RT mode 6
Buck switching frequency (fixed-frequency PWM, 200 kΩ RT) ƒS 523 585 640 kHz Under fixed-frequency PWM mode, with 200 kΩ connected between RT/CLK and GND pins 6
Buck switching frequency range (CLK mode) ƒS 300 2200 kHz Under CLK mode 6
RT/CLK high threshold 1.9 2.2 V 6
RT/CLK low threshold 0.5 0.7 V 6
Initial start-up voltage 6 36 V 6
LDO line regulation ΔVO(ΔVI) 20 mV V(VIN_LDO) = 6 V to 30 V, I(LDO_OUT) = 10 mA, V(LDO_OUT) = 3.3 V 6
LDO dropout voltage (V(VIN_LDO), V(LDO_OUT)) VDROPOUT 300 450 mV I(LDO_OUT) = 200 mA 7
LDO output current I(LDO_OUT) 280 mA V(LDO_OUT) in regulation, V(VIN) ≥ 4V 7
Operating input voltage on VIN_LDO pin VI(VIN_LDO) 3 36 V V(LDO_OUT) in regulation 7
LDO voltage reference at FB2 V(ref2) 0.788 0.8 0.812 V V(LDO_OUT) = 1.1 V to 5.5 V 7
LDO output current-limit ICL(LDO_OUT) 280 1000 mA V(LDO_OUT) = 0 V (the LDO_OUT pin is shorted to ground) 7
LDO quiescent current IQ(LDO) 35 50 μA 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 7
LDO output capacitor (V(LDO_OUT) ≥ 3.3 V) C(LDO_OUT) 1 40 μF ESR = 0.001 Ω to 100 mΩ; V(LDO_OUT) ≥ 3.3 V 7
Buck soft-start discharge current at 25°C IDischarge(SS) 50 400 μA V(SS) = 1 V, EN1 = 0, TA = 25°C 6
Buck nRST reset threshold 85 90 95 % V(FB1) decreasing 7
Thermal resistance junction-to-ambient RθJA 41 °C/W 5
Thermal resistance junction-to-board RθJB 25.4 °C/W 5
Thermal resistance junction-to-case (bottom) RθJC(bot) 2.7 °C/W 5

CAD (KiCad official)

  • Symbol: TPS65321AQPWPRQ1
  • Footprint: Package_SO:TSSOP-14-1EP_4.4x5mm_P0.65mm
  • 3D model: TSSOP-14-EP (KiCad packages3D, STEP)
  • 3D model files: tps65321aqpwprq1-etched.step / tps65321aqpwprq1-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); tps65321aqpwprq1.step / tps65321aqpwprq1.glb are the bare package body.

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

  • Datasheet: Texas Instruments datasheet (46 pp, sha256 730705a404b718e6, retrieved 2026-10-20, tier: lcsc)
  • Extractor: parts-factory 2.0.0 / extract_pins 0.3, primary claude-haiku-5-5 (text), consensus claude-sonnet-5-5 (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF