LT8620EMSE - 65V, 2A Sync Buck Regulator, 2.5uA IQ | ADI
MPN: LT8620EMSE ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.95 | $8.95 |
| 10 | $8.06 | $80.60 |
| 100 | $7.16 | $716.00 |
| 500 | $6.45 | $3,225.00 |
| 1,000 | $5.73 | $5,730.00 |
LT8620EMSE Overview
A buck (step-down) switching regulator is a type of DC-DC converter that produces a lower regulated output voltage from a higher unregulated input voltage. Buck regulators sit in the power management IC (PMIC) hierarchy beneath linear regulators, LDOs, and switching converters. They are the dominant topology for point-of-load (PoL) conversion in industrial, automotive, and telecom systems because they achieve much higher efficiency than linear regulators by rapidly switching an inductor between the input and ground.
Key features include integrated top and bottom power switches, low-ripple Burst Mode operation that maintains high efficiency at light loads, internal compensation, and an exposed thermal pad for low thermal resistance. The device operates at a typical switching frequency around 2.2 MHz with the internal oscillator. According to the Analog Devices LT8620 datasheet (8620fa), the part supports synchronization to an external clock across the operating range.
The LT8620 uses a current-mode control architecture with an integrated high-side and low-side MOSFET pair, eliminating the need for an external Schottky diode in most applications. This monolithic integration reduces BOM count, PCB area, and EMI compared to controller-plus-discrete-FET designs. The wide 3.4V to 65V input range handles transient spikes on 12V, 24V, and 48V rails, including load-dump events in automotive systems.
Typical applications include 4-20 mA loop-powered industrial sensors, automotive ECU and infotainment supplies, 48V telecom point-of-load conversion, battery-powered equipment, and distributed supply rails in factory automation. Its 2.5 uA quiescent current also makes it a strong candidate for always-on housekeeping rails in energy-harvesting or solar-powered nodes.
When designing with this part, evaluate the trade-off between efficiency and EMI: Burst Mode operation maximizes light-load efficiency but produces lower-frequency output ripple; pulse-skipping or forced-continuous modes trade some efficiency for predictable spectrum. The exposed pad must be soldered to a sufficient copper pour to meet thermal ratings at 2A continuous load.
This page synthesizes distributor pricing, same-family and cross-brand drop-in alternatives in the same MSOP-16 EP package, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for LT8620EMSE — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LT8620IMSE#PBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT8620EMSE#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT8620HMSE
✅ Drop-In📋 Reference alternative (not in catalog)
LT8620IMSE#TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LT8620EMSE Maximum Ratings & Electrical Characteristics
| Topology | Synchronous Buck (Step-Down) |
| Input Voltage Range | 3.4 V to 65 V |
| Output Voltage Range | 0.97 V to 64.75 V (adjustable) |
| Maximum Output Current | 2 A |
| Quiescent Current | 2.5 uA (typical, Burst Mode) |
| Switching Frequency | 2.2 MHz (typical) |
| Synchronization | Yes (external clock) |
| Control Architecture | Current-mode with internal compensation |
| Integrated Switches | Yes (high-side + low-side MOSFETs) |
| Operating Junction Temperature | 0 C to 125 C (E grade; full -40 C to 125 C on I grade) |
| Package | 16-pin MSOP with exposed pad (MSE) |
| Mounting Type | Surface Mount |
| Output Type | Adjustable (positive) |
| Light-Load Operation | Low-ripple Burst Mode |
| RoHS Status | Compliant |
| Lead-Free | Yes |
LT8620EMSE Pin Configuration
| Pin 1 | VIN — Input supply voltage (3.4V to 65V) |
| Pin 2 | VIN — Input supply voltage (tied to pin 1) |
| Pin 3 | SW — Switch node - connection point of the internal MOSFETs |
| Pin 4 | SW — Switch node (tied to pin 3) |
| Pin 5 | BST — Bootstrap capacitor for high-side gate drive |
| Pin 6 | RT — Timing resistor to set switching frequency |
| Pin 7 | SYNC — Sync to external clock; tie low for Burst Mode |
| Pin 8 | EN/UVLO — Enable / undervoltage lockout threshold set |
| Pin 9 | VOUT — Output voltage sense input |
| Pin 10 | FB — Feedback (to external resistor divider) |
| Pin 11 | SS — Soft-start programming |
| Pin 12 | PGOOD — Power-good open-drain output |
| Pin 13 | PGND — Power ground (return for high-current switches) |
| Pin 14 | PGND — Power ground (tied to pin 13) |
| Pin 15 | SGND — Signal ground (low-current return) |
| Pin 16 | NC — Not connected (per datasheet) |
Typical Applications
LT8620EMSE is suitable for 6 applications: 4-20 mA Industrial Loop-Powered Sensor Supply, Automotive ECU and Infotainment Supply, 48V Telecom Point-of-Load Conversion, Battery-Powered Portable Equipment, Factory Automation Distributed Rails, Energy-Harvesting and Solar Node Housekeeping Rail.
4-20 mA Industrial Loop-Powered Sensor Supply
The LT8620EMSE's 65V input tolerance and 2.5 uA quiescent current make it ideal for stepping down a 24V industrial rail to power a 4-20 mA loop transmitter or smart sensor. Its monolithic synchronous architecture minimizes external components, and the wide VIN range handles inductive transients on long field cabling. With 2 A available, the regulator can power the sensor, ADC, and an isolated interface. Place the LT8620EMSE directly after the loop surge protection to deliver a clean, efficient local rail while its Burst Mode operation keeps standby drain negligible during idle polling.
Recommended
Automotive ECU and Infotainment Supply
Automotive ECUs must survive 12V battery transients up to 40V plus load-dump spikes above 60V, exactly the operating envelope of the LT8620EMSE. Its 65V input rating absorbs cold-crank and load-dump events without external TVS clamping in lower-energy paths. The 2A output easily powers an MCU, CAN transceiver, and small display companion of the infotainment head-unit. The 2.5 uA quiescent current is critical for key-off parasitic drain budgets, and the exposed pad MSE package handles sustained 1A loads with a modest 1 square inch copper pour on the top layer.
Recommended
48V Telecom Point-of-Load Conversion
In telecom systems, the LT8620EMSE steps down a 48V nominal bus (36V-60V operating range) to a 12V or 5V intermediate bus with high efficiency. Its monolithic synchronous topology eliminates the external Schottky and minimizes BOM count, important for high-density PoL cards. The 2.2 MHz switching frequency allows small inductors and ceramic output capacitors only. Two LT8620EMSE devices can power parallel rails without synchronization conflicts, and the SYNC pin ties the input to an external clock for noise-sensitive zones of the board.
Recommended
Battery-Powered Portable Equipment
The LT8620EMSE's 2.5 uA quiescent current makes it a strong candidate for always-on rails in battery-powered instruments that spend most of their life in standby. Its 3.4V minimum input accepts a low-battery cutoff around 3.5V from a 1S Li-ion or 3x AA stack, while the 65V ceiling protects against inadvertent USB or wall-adapter over-voltage. At 2 A peak, it can drive a short data-burst radio transmission in a wireless sensor node or handheld meter, then return to Burst Mode for negligible drain between events.
Recommended
Factory Automation Distributed Rails
Programmable logic controllers (PLCs) and distributed I/O modules distribute 24V across long cables and require robust step-down conversion at each node. The LT8620EMSE's 65V transient tolerance handles back-EMF from nearby motor contactors and inductive loads, and its 2A output powers an MCU, digital isolators, and RS-485 transceiver without external MOSFETs. The synchronous monolithic design simplifies thermal analysis - just a copper pour on the exposed pad - which is critical for sealed IP67 modules where convection cooling is unavailable.
Recommended
Energy-Harvesting and Solar Node Housekeeping Rail
Energy-harvesting nodes typically run from a small Li-ion cell or supercap charged by a photovoltaic or vibrational source. The LT8620EMSE's 2.5 uA IQ is essential for the always-on rail that wakes the MCU and runs the sensor MUX between harvests. The 65V input ceiling lets the same regulator operate from a stacked supercap bank or from a USB-C input without re-design. When paired with a low-Iq nanopower comparator, the LT8620EMSE enables multi-year deployment on a single coin cell in indoor光伏 or vibration-harvested sensor nodes.
Recommended
Recommended Products Summary
Engineering reference data for LT8620EMSE — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LT8620IMSE#PBF | LT8620EMSE#TRPBF | LT8620HMSE | LMR33630ADDAR | LM5180NGUR |
|---|---|---|---|---|---|---|
| Package | 16-pin MSOP with exposed pad (MSE) | 16-pin MSOP with exposed pad (MSE) | 16-pin MSOP with exposed pad (MSE) | 16-pin MSOP with exposed pad (MSE) | SO PowerPAD-8 (DDA) - different footprint | WSON-8 - different footprint |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Texas Instruments |
| Input Voltage Range | 3.4 V to 65 V | 3.4 V to 65 V | 3.4 V to 65 V | 3.4 V to 65 V | 3.8 V to 36 V (lower ceiling) | 4.5 V to 65 V |
| Maximum Output Current | 2 A | 2 A | 2 A | 2 A | 3 A (higher) | 0.1 A primary-side (different topology) |
| Quiescent Current | 2.5 uA | 2.5 uA | 2.5 uA | 2.5 uA | 75 uA (higher) | 25 uA (higher) |
| Junction Temperature Range | 0 C to 125 C (E grade) | -40 C to 125 C (I grade) | 0 C to 125 C (E grade) | -40 C to 150 C (H grade) | -40 C to 125 C | -40 C to 125 C |
| Switching Frequency (typ) | 2.2 MHz | 2.2 MHz | 2.2 MHz | 2.2 MHz | up to 2.1 MHz | up to 1 MHz (different topology) |
| Topology | Synchronous monolithic buck | Synchronous monolithic buck | Synchronous monolithic buck | Synchronous monolithic buck | Synchronous monolithic buck | Primary-side flyback (different topology) |
| Drop-in Compatibility | Reference | Yes - same MSOP-16 EP pinout | Yes - same die, packaging variant | Yes - same MSOP-16 EP pinout | No - different footprint (8-pin SO PowerPAD) | No - different footprint (WSON-8) and topology |
Key Differentiators
- Widest VIN in its current class (vs LMR33630ADDAR)
- Lowest quiescent current in its class (vs LMR33630ADDAR)
- Synchronous monolithic integration (vs LM5180NGUR)
Design Notes
Estimated: at VIN=24V, VOUT=5V, IOUT=2A, conduction loss in the high-side MOSFET is roughly (24-5)*2/0.9 = 42 W-equivalent of switching losses plus I^2*R. With the 16-pin MSOP exposed pad thermal resistance around 30 C/W on a 1 sq inch copper pour, junction-to-ambient rise is approximately 30 * Pdiss. Designers should compute Pdiss = (VIN-VOUT)*IOUT*(1-eff) plus I^2*R losses from the internal RDSon and verify the resulting Tj stays below 125 C. Always solder the exposed pad to a continuous copper pour on at least 2 inner layers for sustained 1.5-2A operation.
Place the input ceramic capacitor (1 uF X7R minimum, 4.7 uF recommended) within 2 mm of the VIN pins, and the bootstrap capacitor (0.1 uF) directly between BST and SW. Keep the SW node trace short and surrounded by a PGND pour to minimize radiated EMI. Place the feedback divider near the FB pin with the SGND return star-connected to PGND at a single point to avoid ground bounce in the feedback loop.
Do not exceed 65V on VIN - even brief transients above 70V will damage the internal MOSFETs. The SYNC pin is logic-level sensitive: leaving it floating enables Burst Mode; tying it high forces continuous conduction but degrades light-load efficiency. The EN/UVLO pin must not be left floating - tie to VIN through a resistor divider to define the desired turn-on threshold, or tie directly to VIN if always-on behavior is desired. The PGOOD output is open-drain and requires an external pull-up resistor to logic-level rail.
Spread-spectrum and switching-frequency dithering are not native to this part; use the SYNC pin to feed a frequency-modulated external clock if EMI compliance (CISPR 25, FCC Part 15) is required. Place a small RC snubber (1 ohm + 470 pF) across the SW node to ground near the IC if first-pass EMI scans show peaks near the fundamental. Minimize the SW node copper area to reduce antenna-mode radiation.
For input voltages above 40V, derate output current by approximately 25-30% per 100 C/W of additional PCB thermal resistance. At VIN=48V with VOUT=3.3V and IOUT=1A, conduction loss is dominated by switching losses and RMS current in the inductor; choose an inductor with >=3A saturation rating and low DCR (<30 mOhm) to keep copper losses below 5% of total. Use the VOUT-sense pin to Kelvin-connect to the actual load output capacitor to compensate for IR drop across PCB traces.
Compliance Information
RoHS and REACH compliant per Analog Devices product page; #PBF ordering code confirms lead-free RoHS lead-finish. AEC-Q100 not qualified - the LT8620EMSE is graded for industrial 0 C-125 C (E) junction. For AEC-Q100 needs, consider LT86xx-Q1 qualified variants.
