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Contents

README

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LT8609EMSE#TRPBF

Analog Devices · DC-DC Converters · MSOP-10-EP

LT8609EMSE#TRPBF from Analog Devices, in a MSOP-10-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 BST power_out Provides a drive voltage higher than the input voltage to the topside power switch, and a 0.1µF boost capacitor must be placed as close as possible to the IC with no series resistor.
2 SW output Output of the internal power switches that connects to the inductor and boost capacitor, and this node should be kept small on the PCB for good performance.
3 INTVCC power_out Internal 3.5V regulator bypass pin that powers the internal drivers and control circuits, with a maximum output current of 20mA, a voltage that varies between 2.8V and 3.5V, decoupling with at least 1µF low ESR ceramic, and no external loading.
4 RT passive A resistor is tied between RT and ground to set the switching frequency.
5 SYNC input External clock synchronization input: ground for low-ripple Burst Mode at low loads, tie to a clock to synchronize, leave floating for pulse-skipping mode without spread spectrum, and tie to INTVCC or to a voltage between 3.2V and 5.0V for pulse-skipping with spread spectrum.
6 FB input Feedback pin that the regulator holds at 0.782V, where the feedback resistor divider tap connects.
7 TR/SS input Output tracking and soft-start pin: a voltage below 0.782V makes FB follow TR/SS, an internal 2µA pull-up from INTVCC sets the ramp with a capacitor, and the pin is pulled to ground through 300Ω during shutdown and faults (use a series resistor when driven from a low-impedance source).
8 PG output Open-drain power-good output that stays low until FB is within ±8.5% of the regulation voltage with no fault conditions, and is valid when VIN is above 3.2V regardless of the EN/UV state.
9 VIN power_in Supplies the internal circuitry and the internal topside power switch and must be locally bypassed, with the input capacitor placed as close as possible to the VIN and GND pins.
10 EN/UV input Shuts the part down when low and enables it when high, with a hysteretic threshold of 1.05V rising and 1.00V falling, and it should be tied to VIN if the shutdown feature is not used.
11 GND power_in Exposed pad that must be connected to the negative terminal of the input capacitor and soldered to the PCB to lower the thermal resistance.

Key specifications

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

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, EN/UV, PG voltage 42 V Absolute maximum rating 2
FB, TR/SS voltage 4 V Absolute maximum rating 2
SYNC Voltage 6 V Absolute maximum rating 2
Operating Junction Temperature Range -40 125 °C LT8609E/LT8609AE/LT8609BE (MSE package) 2
Storage Temperature Range -65 150 °C 2
Minimum Input Voltage 2.7 3 3.2 V Over full operating temperature range (l) 3
VIN Quiescent Current 1 4 µA VEN/UV = 0V, VSYNC = 0V (LT8609/LT8609A) 3
VIN Quiescent Current 1.7 12 µA VEN/UV = 2V, Not Switching, VSYNC = 0V (LT8609/LT8609A); over full temperature range (l) 3
VIN Current in Regulation 46 90 µA VIN = 6V, VOUT = 2.7V, Output Load = 100µA (LT8609/LT8609A); over full temperature range (l) 3
VIN Current in Regulation 480 700 µA VIN = 6V, VOUT = 2.7V, Output Load = 1mA (LT8609/LT8609A); over full temperature range (l) 3
Feedback Reference Voltage 0.778 0.782 0.786 V VIN = 6V, ILOAD = 100mA (LT8609/LT8609A) 3
Feedback Reference Voltage 0.77 0.782 0.794 V VIN = 6V, ILOAD = 100mA (LT8609/LT8609A); over full temperature range (l) 3
Feedback Voltage Line Regulation 0.02 0.04 %/V VIN = 4.0V to 40V; over full temperature range (l) 3
Feedback Pin Input Current -20 20 nA VFB = 1V; over full temperature range (l) 3
Minimum On-Time 45 75 ns ILOAD = 1.5A, SYNC = 0V; over full temperature range (l) 3
Minimum On-Time 45 60 ns ILOAD = 1.5A, SYNC = 1.9V; over full temperature range (l) 3
Minimum Off Time 90 130 ns No conditions printed; column assignment of the two printed values inferred (see review) 3
Oscillator Frequency 155 200 245 kHz RT = 221k, ILOAD = 0.5A (LT8609/LT8609A); over full temperature range (l) 3
Oscillator Frequency 640 700 760 kHz RT = 60.4k, ILOAD = 0.5A (LT8609/LT8609A); over full temperature range (l) 3
Oscillator Frequency 1.925 2 2.075 MHz RT = 18.2k, ILOAD = 0.5A (LT8609/LT8609A); over full temperature range (l) 3
Top Power NMOS Current Limit 3.4 4.5 5.7 A Over full temperature range (l) 3
EN/UV Pin Threshold 0.99 1.05 1.11 V EN/UV Rising; over full temperature range (l) 3
EN/UV Pin Current -20 20 nA VEN/UV = 2V (LT8609/LT8609A); over full temperature range (l) 3
PG Upper Threshold Offset from VFB 5 8.5 13 % LT8609/LT8609A: VFB Rising; over full temperature range (l) 3
PG Lower Threshold Offset from VFB 5 8.5 13 % LT8609/LT8609A: VFB Falling; over full temperature range (l) 4
PG Leakage -200 200 nA VPG = 42V; over full temperature range (l) 4
PG Pull-Down Resistance 550 1200 Ω VPG = 0.1V; column assignment of the two printed values inferred (see review) 4
TR/SS Source Current 1 2 3 µA Over full temperature range (l) 4
TR/SS Pull-Down Resistance 300 900 Ω Fault Condition, TR/SS = 0.1V; column assignment of the two printed values inferred (see review) 4
Spread Spectrum Modulation Frequency 1 3 6 kHz VSYNC = 3.3V (LT8609/LT8609A) 4
Thermal resistance junction to ambient (eJA) 40 °C/W MSE 10-lead plastic MSOP package; single printed value, entered as typ (see review) 2

CAD (KiCad official)

  • Symbol: LT8609EMSE#TRPBF
  • Footprint: Package_SO:MSOP-10-1EP_3x3mm_P0.5mm_EP1.68x1.88mm
  • 3D model: MSOP-10-EP (KiCad packages3D, STEP)
  • 3D model files: lt8609emse-trpbf-etched.step / lt8609emse-trpbf-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lt8609emse-trpbf.step / lt8609emse-trpbf.glb are the bare package body.

Provenance

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

  • Datasheet: Analog Devices datasheet (26 pp, sha256 587a9fb33e1fb23a, retrieved 2026-10-18, 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