Monolithic Power Systems Inc. MP1497DJ-LF-Z

Overview

MP1497DJ-LF-Z from Monolithic Power Systems is a synchronous step-down DC/DC converter with integrated 80mΩ high-side and 30mΩ low-side MOSFETs, delivering up to 3A continuous output current across a 4.5V–16V input range. It operates at a fixed 500kHz switching frequency (±12%), supports external clock synchronization (200kHz–2MHz), and features programmable soft-start, over-current protection with hiccup mode, and thermal shutdown - deployed in notebook I/O power and flat-panel display supplies.

For engineers reviewing the MP1497DJ-LF-Z datasheet, MP1497DJ-LF-Z pinout, MP1497DJ-LF-Z application, or MP1497DJ-LF-Z equivalent, key selection criteria include internal MOSFET R_DS(on), 0.8V feedback reference accuracy (±2.5% over –40°C to +85°C), EN/SYNC dual-function pin behavior, and TSOT-23-8 thermal performance (θ_JA = 100°C/W).

Technical Context

The MP1497DJ-LF-Z implements peak-current-mode control with a fixed-frequency oscillator and internal error amplifier referenced to a trimmed 0.807V bandgap voltage. Its proprietary bootstrap charging circuit maintains BST voltage regulation via VIN, with UVLO protection on the floating driver (2.2V rising threshold, 150mV hysteresis).

Current-limit protection triggers at 4.2A minimum (typ. 5A) under ≤40% duty cycle, and short-circuit response enters hiccup mode when FB falls below 400mV - reducing average output current to limit thermal stress. The EN/SYNC pin combines digital enable logic (1.2–1.6V rising threshold) with external clock synchronization capability (200kHz–2MHz).

Key Specifications

Pinout & Package

MP1497DJ-LF-Z is housed in an 8-pin TSOT-23 package (3.0mm × 3.0mm × 0.9mm), optimized for high-density PCB layouts with exposed thermal pad (connected to GND). Pin spacing is 0.65mm; pin 1 is bottom-left when viewing top marking left-to-right.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with MP2333DJ-LF-Z, the MP1497DJ-LF-Z offers proven field reliability and simpler compensation but lacks sub-1V reference accuracy and ultra-low IQ. Against RT7295BGJ8F, it trades PG functionality and higher VIN tolerance for integrated BST drive and smaller solution size.

Availability

MP1497DJ-LF-Z is available at Aetrix Electronics and suitable for notebook I/O power, flat-panel display logic supplies, and distributed power system intermediate bus conversion requiring stable component supply and long-term industrial availability.

Supply support for MP1497DJ-LF-Z 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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP1497 belongs to MPS's high-frequency synchronous buck converter product line, engineered for space-constrained consumer and computing applications where integration, efficiency, and thermal performance are prioritized over ultra-low quiescent current.

FAQ

What is the maximum recommended output current for MP1497DJ-LF-Z under continuous operation?

The MP1497DJ-LF-Z delivers 3A continuous output current when mounted on a standard 4-layer PCB with adequate copper area and airflow. At 12V_IN/3.3V_OUT, thermal limits are reached near 3A with θ_JA = 100°C/W; derating to 2.5A is advised for sealed enclosures or ambient temperatures above 60°C.

Can MP1497DJ-LF-Z be synchronized to an external clock, and what are the timing requirements?

Yes - the EN/SYNC pin accepts external clock signals from 200kHz to 2MHz. The external clock must have a pulse width less than 1.7μs and rise after the output voltage is established (≥2ms post-enable). Synchronization occurs on the rising edge, aligning the internal oscillator phase to the external source.

How does the hiccup-mode over-current protection behave during a sustained short circuit?

When FB drops below 400mV (indicating severe overload or short), the MP1497DJ-LF-Z disables switching and waits ~30ms before attempting restart. If the fault persists, it repeats the cycle - limiting average output current to ~100mA and die temperature to safe levels without latching off permanently.

What is the purpose of the 10Ω resistor recommended between SW and BST pins?

The 10Ω resistor dampens high-frequency ringing on the BST node caused by parasitic inductance in the bootstrap loop. This reduces voltage overshoot across the high-side gate oxide, improves reliability, and minimizes EMI emissions from the SW-BST path - especially critical at 500kHz with fast MOSFET transitions.

Is MP1497DJ-LF-Z RoHS-compliant and lead-free?

Yes - MP1497DJ-LF-Z carries the "LF" suffix per MPS ordering nomenclature, indicating lead-free, RoHS-compliant packaging. All solderable surfaces meet JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1) and are compatible with standard reflow profiles.

Why does the datasheet state "NOT RECOMMENDED FOR NEW DESIGNS"?

MPS designates MP1497DJ-LF-Z as legacy due to the introduction of the MP2333DJ-LF-Z, which offers superior specs: lower reference voltage drift (±1.5% vs. ±2.5%), reduced quiescent current (25μA vs. 1mA), and improved thermal resistance (85°C/W vs. 100°C/W). New designs should evaluate MP2333DJ-LF-Z first.

What is the minimum output voltage achievable with MP1497DJ-LF-Z?

The minimum regulated output voltage is 0.8V, set by the internal 0.807V feedback reference. With standard resistor divider tolerances (1%), practical minimum is ~0.79V. Below this, regulation is lost - the device continues switching but cannot maintain feedback loop stability or specified load/line regulation.