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Ray Publish 0.1.0 1474e9f 11d ago

LT3991IMSE#PBF

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

LT3991IMSE#PBF 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 BD passive Connects to the anode of the boost diode and is normally connected to the output.
2 BOOST power_in Provides a drive voltage higher than the input voltage to the internal bipolar NPN power switch, with BOOST pin voltage rated to 75V absolute maximum and no more than 30V above the SW pin.
3 SW output Output of the internal power switch that connects to the inductor, catch diode, and boost capacitor.
4 VIN power_in Supplies current to the internal circuitry and internal power switch over a 4.3V to 55V input range, with an absolute maximum of 55V, and must be locally bypassed.
5 EN input Shuts the part down when low and enables it when high, with a hysteretic threshold of 1.005V rising and 0.975V falling and an absolute maximum of 55V.
6 FB input Regulates to 1.19V and receives the feedback resistor divider tap, with a phase lead capacitor (typically 10pF) connected between FB and VOUT and a 6V absolute maximum.
7 SS passive A capacitor and series resistor tied to ground ramp up the peak current limit at start-up, with a typical soft-start resistor of 100k, and floating this pin disables soft-start.
8 RT passive A resistor tied between RT and ground sets the switching frequency.
9 PG output Open-drain power good output that stays low until the FB pin is within 9% of the final regulation voltage, with a 30V absolute maximum voltage rating.
10 SYNC input External clock synchronization input; grounding it selects low ripple Burst Mode operation at low output loads, and its absolute maximum voltage is 6V.
11 GND power_in Ground; the exposed pad must be soldered to the PCB.

Key specifications

Parameter Value
Manufacturer Analog Devices
Package MSOP-10-EP
Category Power Management ICs
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
Quiescent Current from VIN IQ 0.7 1.2 μA VEN Low 3
Quiescent Current from VIN IQ 1.7 2.7 μA VEN High, VSYNC Low 3
Quiescent Current from VIN IQ 4.5 μA VEN High, VSYNC Low, l (full operating temperature range) 3
Minimum Input Voltage 4 4.3 V Note 4: minimum input voltage depends on application circuit; l 3
LT3991 FB Pin Current 0.1 12 nA VFB = 1.19V, l 3
Feedback Voltage 1.175 1.19 1.205 V l (full operating temperature range) 3
Feedback Voltage 1.165 1.19 1.215 V second printed row, l; grade not labeled 3
FB Voltage Line Regulation 0.0002 0.01 %/V 4.3V < VIN < 40V (Note 4) 3
Switching Frequency 1.6 2 2.4 MHz RT = 11k 3
Switching Frequency 0.8 1 1.2 MHz RT = 35.7k 3
Switching Frequency 160 200 240 kHz RT = 255k 3
Minimum Switch Off Time 150 200 ns 3
Switch Current Limit 1.7 2.3 2.9 A 3
Switch Leakage Current 0.02 1 μA 3
Boost Schottky Reverse Leakage 0.02 1 μA VREVERSE = 12V 3
Minimum Boost Voltage 1.4 1.8 V VIN = 5V, l 3
BOOST Pin Current 25 33 mA ISW = 1A, VBOOST = 15V 3
EN Voltage Threshold 0.95 1.01 1.07 V EN rising, l 3
EN Pin Current 0.2 20 nA 3
LT3991 PG Threshold Offset from VFB 60 100 140 mV VFB rising 3
PG Leakage 0.02 1 µA VPG = 3V 3
PG Sink Current 300 570 μA VPG = 0.4V, l 3
SYNC Threshold 0.6 0.8 1 V 3
SS Source Current 0.6 1 1.6 μA VSS = 1V 3
BOOST Pin Above SW Pin 30 V 2
FB, VOUT, RT, SYNC, SS Voltage 6 V 2
PG, BD Voltage 30 V 2
Boost Diode Current 1 A Note 1 2
Operating Junction Temperature Range (LT3991I) -40 125 °C 2
Storage Temperature Range -65 150 °C 2
Lead Temperature (Soldering, 10 sec) 300 °C MSE package only 2
Thermal Resistance Junction-to-Ambient θJA 45 °C/W MSE package 2
Thermal Resistance Junction-to-Case θJC 10 °C/W MSE package 2
Minimum Switch On Time 110 ns 3
Switch VCESAT 440 mV ISW = 1A 3
Boost Schottky Forward Voltage 800 mV ISH = 100mA 3
EN Voltage Hysteresis 30 mV 3
LT3991 PG Hysteresis 20 mV 3
SYNC Pin Current 0.1 nA 3

CAD (KiCad official)

  • Symbol: LT3991IMSE#PBF
  • Footprint: Package_SO:MSOP-10-1EP_3x3mm_P0.5mm_EP1.68x1.88mm
  • 3D model: MSOP-10-EP (KiCad packages3D, STEP)
  • 3D model files: lt3991imse-pbf-etched.step / lt3991imse-pbf-etched.glb carry the MPN laser-etched on the die in a toggleable Adom.LaserEtch group (Fusion-ready); lt3991imse-pbf.step / lt3991imse-pbf.glb are the bare package body.

Provenance

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

  • Datasheet: Analog Devices datasheet (24 pp, sha256 05394db5ad4d382a, retrieved 2026-10-28, tier: manufacturer)
  • 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