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README

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LT3973EDD#TRPBF

Analog Devices · DC-DC Converters · DFN-10-EP(3x3)

LT3973EDD#TRPBF from Analog Devices, in a DFN-10-EP(3x3). Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

Pinout

Pin Name Type Function
1 FB input Feedback pin for the adjustable LT3973. The internal error amplifier regulates FB to 1.21V; connect the tap of the external resistor divider from VOUT to GND here. FB bias current is typically 0.1nA (20nA max).
2 OUT power_in Output-sense pin used by the LT3973 to regulate the VIN-to-VOUT voltage during dropout conditions and to draw current for charging the boost capacitor. Connect to the regulated output; if the programmed output is greater than 14V, tie this pin to GND. Absolute max 14V.
3 EN/UVLO input Enable / undervoltage-lockout input. The part is in shutdown when this pin is low and active when high; the internal threshold is 1.19V rising with 30mV hysteresis (accurate only when VIN ≥ 4.2V). Tie to VIN if the shutdown feature is unused, or ground to force shutdown. Absolute max 42V.
4 VIN power_in Main supply input, 4.2V to 42V operating (42V absolute max). VIN supplies the internal circuitry and the internal power switch. Must be locally bypassed with a low-ESR ceramic capacitor.
5 GND power_in Device ground reference. Must be tied together with the exposed pad (pin 11) on the PCB. Serves as the return for VIN, EN/UVLO, and internal circuitry.
6 SW output Switch node - output of the internal high-side NPN power switch and drain of the integrated catch Schottky. Connect this pin to the external inductor. Sees VIN plus a diode drop during off-time; internal catch-diode current limit is typically 1.15A.
7 BOOST passive Bootstrap pin used to generate a drive voltage higher than VIN for the internal NPN power switch. A ceramic boost capacitor (typ. 0.47µF) is connected from BOOST to SW. Absolute max 55V (25V above SW).
8 BD power_in Boost-diode anode. Connect through the boost capacitor charging path - this pin drives the anode of the internal boost Schottky and also supplies current to the LT3973's internal regulator whenever BD is above 3.2V. Absolute max 25V.
9 PG output Power-good open-drain output from an internal comparator. PG remains low until FB is within 10% of the final regulation voltage; it is valid once VIN > 4.2V and EN/UVLO is high. Sink capability typ. 350µA at 0.4V; leakage 0.01µA at 3V. Add an external pull-up resistor.
10 RT passive Switching-frequency programming pin. Connect an external resistor from RT to GND to program the oscillator between 200kHz and 2.2MHz (e.g. 41.2k → 2.15MHz, 158k → 790kHz, 768k → 195kHz).
11 GND (Exposed Pad) power_in Exposed thermal pad on the underside of the DFN package. Electrically GND - must be soldered to the PCB ground plane for proper electrical and thermal performance (θJA = 40°C/W for the DD package).

Key specifications

Parameter Value
Manufacturer Analog Devices
Package DFN-10-EP(3x3)
Category Power Management (PMIC)
Pins 11

Ordering variants

Same part, different packaging or reel option.

  • LT3973EDD#PBF
  • LT3973EDD#TRPBF
  • LT3973EDD#TRPBFIDD#PBF
  • LT3973EDD#TRPBFIDD#TRPBF
  • LT3973EDD#TRPBFHDD#PBF
  • LT3973EDD#TRPBFHDD#TRPBF
  • LT3973EDD#TRPBFEDD-3.3#PBF
  • LT3973EDD#TRPBFEDD-3.3#TRPBF
  • LT3973EDD#TRPBFIDD-3.3#PBF
  • LT3973EDD#TRPBFIDD-3.3#TRPBF
  • LT3973EDD#TRPBFHDD-3.3#PBF
  • LT3973EDD#TRPBFHDD-3.3#TRPBF
  • LT3973EDD#TRPBFEDD-5#PBF
  • LT3973EDD#TRPBFEDD-5#TRPBF
  • LT3973EDD#TRPBFIDD-5#PBF
  • LT3973EDD#TRPBFIDD-5#TRPBF
  • LT3973EDD#TRPBFHDD-5#PBF
  • LT3973EDD#TRPBFHDD-5#TRPBF
  • LT3973EDD#TRPBFEMSE#PBF
  • LT3973EDD#TRPBFEMSE#TRPBF
  • LT3973EDD#TRPBFIMSE#PBF
  • LT3973EDD#TRPBFIMSE#TRPBF
  • LT3973EDD#TRPBFHMSE#PBF
  • LT3973EDD#TRPBFHMSE#TRPBF
  • LT3973EDD#TRPBFEMSE-3.3#PBF
  • LT3973EDD#TRPBFEMSE-3.3#TRPBF
  • LT3973EDD#TRPBFIMSE-3.3#PBF
  • LT3973EDD#TRPBFIMSE-3.3#TRPBF
  • LT3973EDD#TRPBFHMSE-3.3#PBF
  • LT3973EDD#TRPBFHMSE-3.3#TRPBF
  • LT3973EDD#TRPBFEMSE-5#PBF
  • LT3973EDD#TRPBFEMSE-5#TRPBF
  • LT3973EDD#TRPBFIMSE-5#PBF
  • LT3973EDD#TRPBFIMSE-5#TRPBF
  • LT3973EDD#TRPBFHMSE-5#PBF
  • LT3973EDD#TRPBFHMSE-5#TRPBF

CAD (KiCad official)

  • Symbol: LT3973EDD#TRPBF
  • Footprint: Package_DFN_QFN:DFN-10-1EP_3x3mm_P0.5mm_EP1.55x2.48mm
  • 3D model: DFN-10-EP(3x3) (KiCad packages3D, STEP)

Provenance

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

  • Datasheet: Analog Devices datasheet (24 pp, sha256 8b84083bfbac6278, retrieved 2026-08-17, tier: lcsc)
  • Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
  • CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF