Monolithic Power Systems Inc. EV1517DR-00B

Overview

EV1517DR-00B from Monolithic Power Systems is a fully assembled and tested evaluation board for the MP1517DR DC-DC converter IC, configured as a 3.3V/1A SEPIC regulator operating from a 3V–4.2V input. It implements soft-start, cycle-by-cycle current limiting, and input under-voltage lockout, and uses a 1.1MHz switching frequency with external compensation to support wide load and input variations in handheld power applications.

For engineers reviewing the EV1517DR-00B datasheet, EV1517DR-00B pinout, EV1517DR-00B application, or EV1517DR-00B equivalent, this board enables rapid validation of MP1517DR-based SEPIC designs requiring compact size, output disconnect at shutdown, and high efficiency (>80%) across 1mA–1A loads.

Technical Context

The EV1517DR-00B implements a current-mode controlled SEPIC topology using the MP1517DR IC, supporting input-to-output voltage crossover (VIN can be below or above VOUT) with inherent output disconnect during shutdown. Its 1.1MHz fixed-frequency operation reduces inductor and capacitor size while maintaining stable regulation across 3V–4.2V input and 3.3V/1A output conditions.

Key control features include an enable (EN) pin for system-level power sequencing, a feedback (FB) pin referenced to 0.7V, and a compensation (COMP) pin for loop stability tuning. The board integrates a 3.3µH coupled inductor (DRQ125-3R3), Schottky diode (B340LA-13-F), and ceramic input/output capacitors optimized for low ESR and high ripple current handling.

Key Specifications

Availability

EV1517DR-00B is available at Aetrix Electronics and suitable for handheld computers, digital still/video cameras, and cell phone camera flash systems requiring stable component supply, fast prototyping turnaround, and validated SEPIC reference design performance.

Supply support for EV1517DR-00B includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with core expertise in DC-DC conversion, LED drivers, and motor drivers for portable and industrial applications.

The MP1517 product line delivers high-efficiency, high-frequency SEPIC/boost regulators targeting space-constrained battery-powered devices where input voltage may dip below output during discharge cycles.

FAQ

What input voltage range does the EV1517DR-00B support?

The board accepts 3V to 4.2V DC input, matching the discharge profile of a single Li-ion or Li-polymer cell. This range ensures full functionality across battery states without external regulation, and is verified in the MP1517DR's operational specification and board-level testing.

How is the output voltage adjusted on this evaluation board?

VOUT is set by the R1/R2 resistor divider on the FB pin, with R2 fixed at 10kΩ and VFB = 0.7V. Replacing R1 (37.4kΩ default) with a new value calculated using VOUT = 0.7V × (1 + R1/R2) allows precise adjustment - e.g., 41.2kΩ yields 3.6V.

Does the board provide output disconnect during shutdown?

Yes. When the EN pin is pulled low, the MP1517DR disables switching and disconnects the output path, preventing backfeed into the input source. This behavior is inherent to the IC's architecture and confirmed in the board's functional test report and schematic.

What is the purpose of the COMP pin on the EV1517DR-00B?

The COMP pin connects to the error amplifier output and is used for external loop compensation. On this board, it interfaces with C3 (4.7nF) and R3 (5.1kΩ) to stabilize the current-mode control loop across varying input, output, and load conditions per MP1517DR's compensation guidelines.

Can the EV1517DR-00B be used for boost-only configurations?

No - the board is specifically laid out for SEPIC operation using a coupled inductor (T1, DRQ125-3R3) and dual-switch node routing. While the MP1517DR IC supports both boost and SEPIC modes, this evaluation board's PCB layout, component selection, and test validation are exclusively for SEPIC topology.