LTC3621 - 17V, 1A Synchronous Step-Down Regulator with 3.5μA Quiescent Current
Datasheet 
DocumentationDatasheet
Reliability Data
Press Release
- 17V, 2.25MHz, Synchronous Step-Down Regulator Delivers 1A & Requires Only 3.5µA of Quiescent Current
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- LTC3621 Demo Circuit - 17V, 1A, 1MHz Monolithic Synchronous Buck Regulator (2.7-17V to 1.2V @ 1A)
- LTC3621-2 Demo Circuit - 17V, 1A, 2.25MHz Monolithic Synchronous Buck Regulator (2.7-17V to 1.2V @ 1A)
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Features
- Wide VIN Range: 2.7V to 17V
- Wide VOUT Range: 0.6V to VIN
- 95% Max Efficiency
- Low IQ < 3.5μA, Zero-Current Shutdown
- Constant Frequency (1MHz/2.25MHz)
- Full Dropout Operation with Low IQ
- 1A Rated Output Current
- ±1% Output Voltage Accuracy
- Current Mode Operation for Excellent Line and Load Transient Response
- Synchronizable to External Clock
- Pulse-Skipping, Forced Continuous, Burst Mode® Operation
- Internal Compensation and Soft-Start
- Overtemperature Protection
- Compact 6-Lead DFN (2mm × 3mm) Package or Thermally-Enhanced MS8E Package with Power Good Output and Independent SGND Pin
Typical Application
Description
The LTC®3621/LTC3621-2 is a high efficiency 17V, 1A synchronous monolithic step-down regulator. The switching frequency is fixed to 1MHz or 2.25MHz with a ±40% synchronizing range. The regulator features ultralow quiescent current and high efficiencies over a wide VOUT range.
The step-down regulator operates from an input voltage range of 2.7V to 17V and provides an adjustable output range from 0.6V to VIN while delivering up to 1A of output current. A user-selectable mode input is provided to allow the user to trade off ripple noise for light load efficiency; Burst Mode operation provides the highest efficiency at light loads, while pulse-skipping mode provides the lowest voltage ripple. The MODE pin can also be used to allow the user to sync the switching frequency to an external clock.
LTC3621 Options
| PART NAME | FREQUENCY | VOUT |
| LTC3621 | 1.00MHz | Adjustable |
| LTC3621-3.3 | 1.00MHz | 3.3V |
| LTC3621-5 | 1.00MHz | 5V |
| LTC3621-2 | 2.25MHz | Adjustable |
| LTC3621-23.3 | 2.25MHz | 3.3 |
| LTC3621-25 | 2.25MHz | 5V |
2x3 DFN-6,MS-8
Package Variations and Pricing
| Part Number | Package | Pins | Temp | Price (1-99) |
Price (1k)* |
|---|---|---|---|---|---|
| LTC3621EDCB#PBF | DFN | 6 | E | $3.64 | |
| LTC3621EDCB#TRMPBF | DFN | 6 | E | $3.64 | $2.60 |
| LTC3621EDCB#TRPBF | DFN | 6 | E | $3.64 | $2.55 |
| LTC3621EDCB-2#PBF | DFN | 6 | E | $3.64 | |
| LTC3621EDCB-2#TRMPBF | DFN | 6 | E | $3.64 | $2.60 |
| LTC3621EDCB-2#TRPBF | DFN | 6 | E | $3.64 | $2.55 |
| LTC3621EDCB-23.3#PBF | DFN | 6 | E | $3.64 | |
| LTC3621EDCB-23.3#TRMPBF | DFN | 6 | E | $3.64 | $2.60 |
| LTC3621EDCB-23.3#TRPBF | DFN | 6 | E | $3.64 | $2.55 |
| LTC3621EDCB-25#PBF | DFN | 6 | E | $3.64 | |
| LTC3621EDCB-25#TRMPBF | DFN | 6 | E | $3.64 | $2.60 |
| LTC3621EDCB-25#TRPBF | DFN | 6 | E | $3.64 | $2.55 |
| LTC3621EDCB-3.3#PBF | DFN | 6 | E | $3.64 | |
| LTC3621EDCB-3.3#TRMPBF | DFN | 6 | E | $3.64 | $2.60 |
| LTC3621EDCB-3.3#TRPBF | DFN | 6 | E | $3.64 | $2.55 |
| LTC3621EDCB-5#PBF | DFN | 6 | E | $3.64 | |
| LTC3621EDCB-5#TRMPBF | DFN | 6 | E | $3.64 | $2.60 |
| LTC3621EDCB-5#TRPBF | DFN | 6 | E | $3.64 | $2.55 |
| LTC3621EMS8E#PBF | MSOP | 8 | E | $3.64 | $2.55 |
| LTC3621EMS8E#TRPBF | MSOP | 8 | E | $2.61 | |
| LTC3621EMS8E-2#PBF | MSOP | 8 | E | $3.64 | $2.55 |
| LTC3621EMS8E-2#TRPBF | MSOP | 8 | E | $2.61 | |
| LTC3621EMS8E-23.3#PBF | MSOP | 8 | E | $3.64 | $2.55 |
| LTC3621EMS8E-23.3#TRPBF | MSOP | 8 | E | $2.61 | |
| LTC3621EMS8E-25#PBF | MSOP | 8 | E | $3.64 | $2.55 |
| LTC3621EMS8E-25#TRPBF | MSOP | 8 | E | $2.61 | |
| LTC3621EMS8E-3.3#PBF | MSOP | 8 | E | $3.64 | $2.55 |
| LTC3621EMS8E-3.3#TRPBF | MSOP | 8 | E | $2.61 | |
| LTC3621EMS8E-5#PBF | MSOP | 8 | E | $3.64 | $2.55 |
| LTC3621EMS8E-5#TRPBF | MSOP | 8 | E | $2.61 | |
| LTC3621IDCB#PBF | DFN | 6 | I | $4.02 | |
| LTC3621IDCB#TRMPBF | DFN | 6 | I | $4.02 | $2.86 |
| LTC3621IDCB#TRPBF | DFN | 6 | I | $4.02 | $2.81 |
| LTC3621IDCB-2#PBF | DFN | 6 | I | $4.02 | |
| LTC3621IDCB-2#TRMPBF | DFN | 6 | I | $4.02 | $2.86 |
| LTC3621IDCB-2#TRPBF | DFN | 6 | I | $4.02 | $2.81 |
| LTC3621IDCB-23.3#PBF | DFN | 6 | I | $4.02 | |
| LTC3621IDCB-23.3#TRMPBF | DFN | 6 | I | $4.02 | $2.86 |
| LTC3621IDCB-23.3#TRPBF | DFN | 6 | I | $4.02 | $2.81 |
| LTC3621IDCB-25#PBF | DFN | 6 | I | $4.02 | |
| LTC3621IDCB-25#TRMPBF | DFN | 6 | I | $4.02 | $2.86 |
| LTC3621IDCB-25#TRPBF | DFN | 6 | I | $4.02 | $2.81 |
| LTC3621IDCB-3.3#PBF | DFN | 6 | I | $4.02 | |
| LTC3621IDCB-3.3#TRMPBF | DFN | 6 | I | $4.02 | $2.86 |
| LTC3621IDCB-3.3#TRPBF | DFN | 6 | I | $4.02 | $2.81 |
| LTC3621IDCB-5#PBF | DFN | 6 | I | $4.02 | |
| LTC3621IDCB-5#TRMPBF | DFN | 6 | I | $4.02 | $2.86 |
| LTC3621IDCB-5#TRPBF | DFN | 6 | I | $4.02 | $2.81 |
| LTC3621IMS8E#PBF | MSOP | 8 | I | $4.02 | $2.81 |
| LTC3621IMS8E#TRPBF | MSOP | 8 | I | $2.87 | |
| LTC3621IMS8E-2#PBF | MSOP | 8 | I | $4.02 | $2.81 |
| LTC3621IMS8E-2#TRPBF | MSOP | 8 | I | $2.87 | |
| LTC3621IMS8E-23.3#PBF | MSOP | 8 | I | $4.02 | $2.81 |
| LTC3621IMS8E-23.3#TRPBF | MSOP | 8 | I | $2.87 | |
| LTC3621IMS8E-25#PBF | MSOP | 8 | I | $4.02 | $2.81 |
| LTC3621IMS8E-25#TRPBF | MSOP | 8 | I | $2.87 | |
| LTC3621IMS8E-3.3#PBF | MSOP | 8 | I | $4.02 | $2.81 |
| LTC3621IMS8E-3.3#TRPBF | MSOP | 8 | I | $2.87 | |
| LTC3621IMS8E-5#PBF | MSOP | 8 | I | $4.02 | $2.81 |
| LTC3621IMS8E-5#TRPBF | MSOP | 8 | I | $2.87 | |
| LTC3621HMS8E-25#PBF | MSOP | 8 | H | $4.37 | $3.06 |
| LTC3621HMS8E#TRPBF | MSOP | 8 | H | $3.12 | |
| LTC3621HMS8E-2#TRPBF | MSOP | 8 | H | $3.12 | |
| LTC3621HMS8E-5#TRPBF | MSOP | 8 | H | $3.12 | |
| LTC3621HMS8E-5#PBF | MSOP | 8 | H | $4.37 | $3.06 |
| LTC3621HMS8E-23.3#PBF | MSOP | 8 | H | $4.37 | $3.06 |
| LTC3621HMS8E-3.3#PBF | MSOP | 8 | H | $4.37 | $3.06 |
| LTC3621HMS8E-25#TRPBF | MSOP | 8 | H | $3.12 | |
| LTC3621HMS8E-3.3#TRPBF | MSOP | 8 | H | $3.12 | |
| LTC3621HMS8E-2#PBF | MSOP | 8 | H | $4.37 | $3.06 |
| LTC3621HMS8E-23.3#TRPBF | MSOP | 8 | H | $3.12 | |
| LTC3621HMS8E#PBF | MSOP | 8 | H | $4.37 | $3.06 |
| LTC3621EDCB#TR | DFN | 6 | E | $7.28 | $5.10 |
| LTC3621IDCB#TR | DFN | 6 | I | $8.04 | $5.62 |
| LTC3621EDCB-2#TR | DFN | 6 | E | $7.28 | $5.10 |
| LTC3621IDCB-2#TR | DFN | 6 | I | $8.04 | $5.62 |
| LTC3621EDCB-3.3#TR | DFN | 6 | E | $7.28 | $5.10 |
| LTC3621EDCB-5#TR | DFN | 6 | E | $7.28 | $5.10 |
| LTC3621EDCB-25#TR | DFN | 6 | E | $7.28 | $5.10 |
| LTC3621EDCB-23.3#TR | DFN | 6 | E | $7.28 | $5.10 |
| LTC3621IDCB-23.3#TR | DFN | 6 | I | $8.04 | $5.62 |
| LTC3621IDCB-25#TR | DFN | 6 | I | $8.04 | $5.62 |
| LTC3621IDCB-3.3#TR | DFN | 6 | I | $8.04 | $5.62 |
| LTC3621IDCB-5#TR | DFN | 6 | I | $8.04 | $5.62 |
Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC1863A | LTC3621 Demo Board | 1MHz, 2.7V ≤ VIN ≤ 17V, Vout = 1.2V/1.8V/2.5V/3.3V/5V/Adj @ 1A | $100.00 | |
| DC1864A | LTC3621-2 Demo Board | 2.25MHz, 2.7V ≤ VIN ≤ 17V, Vout = 1.2V/1.8V/2.5V/3.3V/5V/Adj @ 1A | $100.00 |