Monolithic Power Systems Inc. MP8869GL-Z

Overview

MP8869GL-Z from Monolithic Power Systems is a 4.5V–17V input, 12A continuous synchronous step-down converter with integrated I²C telemetry, constant-on-time (COT) control, and programmable output voltage (0.6V–1.87V in 10mV steps). It delivers ±1% reference accuracy, 5% I²C readback accuracy for V_OUT and I_OUT, and operates in QFN-14 (3mm×4mm) package. Used in SSD power rails requiring dynamic voltage scaling and real-time telemetry.

For engineers reviewing the MP8869GL-Z datasheet, MP8869GL-Z pinout, MP8869GL-Z application, or MP8869GL-Z equivalent, key selection criteria include I²C-configurable slew rate, selectable PFM/PWM mode, 4 programmable I²C addresses, open-drain power good signaling, and thermal shutdown at 160°C with 20°C hysteresis.

Technical Context

The MP8869GL-Z implements constant-on-time (COT) control with internal ramp compensation, enabling stable operation with ceramic output capacitors and eliminating external ESR dependency. Its dual-loop architecture supports both FB-resistor-based and I²C-programmed regulation modes, with seamless transition between them.

I²C interface provides full telemetry and configuration: output voltage, current limit (14A), switching frequency (400–600kHz), soft-start slew, hiccup/latch-off OCP, and power-saving mode selection. The 4 configurable I²C addresses (60H–66H) enable multi-rail coordination on shared buses without address conflict.

Key Specifications

Pinout & Package

Package: QFN-14 (3mm × 4mm) with exposed thermal pad - optimized for high-power density PCB layouts and efficient heat dissipation in compact SSD and server modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP8859GQ-Z, MP8869GL-Z adds essential telemetry and 4A higher current capacity; versus TPS546D24RSAR, it offers smaller footprint and lower system cost at the expense of PMBus feature depth and absolute accuracy.

Availability

MP8869GL-Z is available at Aetrix Electronics and suitable for solid-state drives, flat-panel displays, and distributed server power systems requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MP8869GL-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 over 20 years of leadership in DC/DC conversion, motor drivers, and LED lighting solutions.

The MP8869 belongs to MPS's high-current, telemetry-enabled buck converter product line, designed specifically for data center, storage, and display applications demanding digital configurability, real-time monitoring, and compact thermal design.

FAQ

What is the maximum supported I²C clock frequency for MP8869GL-Z?

The MP8869GL-Z supports standard-mode (100kHz), fast-mode (400kHz), and high-speed mode (3.4MHz) I²C operation. Electrical specifications confirm SCLH clock frequency up to 3.4MHz with C_b = 100pF, and rise/fall times remain within spec (≤40ns) under typical bus loading conditions.

Can MP8869GL-Z operate without an external feedback resistor divider?

Yes - in I²C mode, the FB pin is internally disconnected and VOUT is directly sensed; output voltage is set digitally via register writes. The FB pin remains unconnected, eliminating resistor tolerance errors and enabling true programmable regulation without external components.

How does the MP8869GL-Z handle pre-biased output conditions during startup?

When the output is pre-biased, the MP8869GL-Z disables HS/LS-FET switching until the internal SS capacitor voltage exceeds the sensed VOUT level. This prevents reverse current flow and ensures controlled, non-destructive startup into pre-charged loads such as hot-swappable SSD modules.

What is the minimum off-time specification, and why does it matter for low-VOUT operation?

The minimum off-time is 185ns. At low output voltages (e.g., 0.6V) and high input (e.g., 12V), duty cycle drops sharply; insufficient off-time would cause frequency collapse and instability. The 185ns spec ensures stable COT operation down to 0.6V with ≥400kHz minimum frequency at VIN = 12V.

Is the PG pin actively driven or open-drain, and what voltage levels trigger assertion?

The PG pin is open-drain with 4mA sink capability. It asserts low when VOUT falls below 0.85VOUT (UV fault) or rises above 1.15VOUT (OV fault); it releases high when VOUT returns to 0.90–1.05VOUT window. A pull-up resistor to VCC or system rail is required for proper logic-level signaling.

Does MP8869GL-Z support forced PWM mode under light load, and how is it enabled?

Yes - forced PWM mode is selected by setting the Mode bit (bit 7 of Register 01) to '1' via I²C. In this mode, the converter maintains continuous conduction regardless of load, eliminating audible noise and ensuring predictable EMI spectrum - critical for noise-sensitive imaging and audio subsystems.

What thermal resistance values apply to the QFN-14 package, and how is θ_JA measured?

The QFN-14 (3mm×4mm) package has θ_JA = 48°C/W and θ_JC = 11°C/W, measured per JESD51-7 on a 4-layer PCB with 2oz copper, 1-in² thermal pad, and 6 vias to inner ground plane. These values assume standard JEDEC test board conditions and define worst-case junction temperature rise under full 12A load.