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The L4973 is a step down monolithic power switching regulator delivering 3.5A at fixed voltages of 3.3V or 5.1V and using a simple external divider output adjustable voltage up to 50V. Realized in BCD mixed technology, the device uses an internal power D-MOS transistor (with a typical RDS(on) of 0.15Ω) to obtain very high efficiency and very fast switching times. Switching frequency up to 300KHz are achievable (the maximum power dissipation of the packages must be observed).
A wide input voltage range between 8V to 55V and output voltages regulated from 3.3V to 40V cover the majority of the today applications. Features of this new generation of DC-DC converter includes pulse by pulse current limit, hiccup mode for output short circuit protection, voltage feed forward regulation, soft start, input/output synchronization, protection against feedback loop disconnection, inhibit for zero current consumption and thermal shutdown. Packages available are in plastic dual in line, DIP- 18 (12+3+3) for standard assembly, and SO20 (12+4+4) for SMD assembly.
Key Features
- Inhibit for zero current consumption (100mA at VCC= 24V)
- Input/output synchronization function
- Thermal shutdown
- Protection against feedback disconnection
- Soft start function
- Output over voltage protection
- Internal current limiting (pulse by pulse and HICCUP mode)
- Zero load current operation (min 1mA)
- Up to 3.5A step down converter
- 3.3V and 5.1V (±1%) fixed output, and adjustable outputs from:
0.5V to 50V (3.3 type) 5.1V to 50V (5.1 type) - Operating input voltage from 8V to 55V
- Voltage feed forward
- Precise 5.1V (1.5%) reference voltage externally available
- Frequency adjustable up to 300kHz
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Quality and Reliability
| Part Number | Marketing Status | Package | Grade | RoHS Compliance Grade | Material Declaration** |
|---|---|---|---|---|---|
| L4973D3.3 | Active | SO-20 | Industrial | Ecopack2 | |
| L4973D3.3-013TR | Active | SO-20 | Industrial | Ecopack1 (*) | |
| L4973D5.1 | Active | SO-20 | Industrial | Ecopack2 | |
| L4973D5.1-013TR | Active | SO-20 | Industrial | Ecopack2 | |
| L4973V3.3 | Active | PDIP 18 | Industrial | Ecopack1 | |
| L4973V5.1 | Active | PDIP 18 | Industrial | Ecopack1 |
(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.
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Sample & Buy
| Part Number | Order from Distributors | Order from ST | Package | Packing Type | Marketing Status | ECCN (US) | Country of Origin | Budgetary Price (US$)*/Qty | |
|---|---|---|---|---|---|---|---|---|---|
| L4973D3.3 | 5 distributors | Buy now | SO-20 | Tube | Active | EAR99 | MALAYSIA | 1.811 / 1k | |
| L4973D5.1-013TR | 5 distributors | Buy now | SO-20 | Tape And Reel | Active | EAR99 | MALAYSIA | 1.861 / 1k | |
| L4973V3.3 | 4 distributors | Get sample | PDIP 18 | Tube | Active | EAR99 | MALAYSIA | 1.693 / 1k | |
| L4973D3.3-013TR | 5 distributors | Buy now | SO-20 | Tape And Reel | Active | EAR99 | MALAYSIA | 1.811 / 1k | |
| L4973D5.1 | 5 distributors | Buy now | SO-20 | Tube | Active | EAR99 | MALAYSIA | 1.861 / 1k | |
| L4973V5.1 | 7 distributors | Get sample | PDIP 18 | Tube | Active | EAR99 | MALAYSIA | 1.778 / 1k |
(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office or our Distributors
