Monolithic Power Systems Inc. MP6601GF-Z

Overview

MP6601GF-Z from Monolithic Power Systems is a bipolar stepper motor driver IC with dual full-bridge outputs, internal current sensing (no external sense resistors), and programmable constant-off-time PWM control. It operates from 4.5V to 35V input, delivers up to 2.5A per phase (thermal-limited), supports full/half/quarter-step modes via PHASE/I0/I1 logic interface, and integrates OCP, OVP, UVLO, thermal shutdown, and open-drain fault reporting - used in compact printer motion control systems.

For engineers reviewing the MP6601GF-Z datasheet, MP6601GF-Z pinout, MP6601GF-Z application, or MP6601GF-Z equivalent, key selection considerations include its TSSOP-28 EP package thermal performance (θJA = 32°C/W), internal 2-bit DAC-based current scaling (100%/71%/38%/Hi-Z), automatic decay mode operation, and compatibility with 3.3V/5V logic without auxiliary supply.

Technical Context

The MP6601GF-Z implements two independent N-channel H-bridges with integrated gate drivers, charge pump (VCP/CP1/CP2), and internal current-sense amplifiers. Its constant-off-time PWM regulation uses an external ROSC resistor (e.g., 200kΩ sets t_OFF ≈ 23µs) and ISET resistor (e.g., 71kΩ sets full-scale I_PEAK = 1.0A) to define switching behavior and current thresholds.

Control logic accepts parallel PHASE, I0, I1 inputs per bridge to select direction and current scale; nSLEEP enables low-power sleep mode with ~1ms wake-up stabilization; nFAULT provides open-drain fault signaling for OCP (6A trip), OVP (37.5V threshold), UVLO (4.5V rising), and thermal shutdown (165°C).

Key Specifications

Pinout & Package

MP6601GF-Z is housed in a thermally enhanced TSSOP-28 EP package (9.7mm × 4.4mm × 1.1mm) with exposed pad for PCB heat sinking. The package supports high-power density designs requiring >3W continuous dissipation at ambient temperatures up to +85°C when properly laid out with thermal vias and ground plane coupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bipolar stepper motor driver applications.

Compared with TB6600HG and DRV8825, MP6601GF-Z uniquely combines internal current sensing, integrated OVP/UVLO/OTP, and 3.3V/5V logic compatibility in a single TSSOP-28 EP package - reducing component count and improving reliability in cost-sensitive embedded motion systems.

Availability

MP6601GF-Z is available at Aetrix Electronics and suitable for printer paper feed mechanisms, POS terminal actuators, label dispenser positioning, and industrial CNC panel jog controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP6601GF-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 distribution through authorized partners.

The MP6601 product line targets compact, cost-sensitive motion control applications - delivering integrated stepper drivers with internal sensing, robust protection, and minimal external components for printers, scanners, and automation peripherals.

FAQ

What is the maximum continuous output current for MP6601GF-Z in TSSOP-28 EP package?

The MP6601GF-Z supports up to 2.5A per phase continuously when mounted on a 4-layer PCB with full thermal vias to inner ground planes and adequate copper area. This rating assumes ambient temperature ≤+85°C and accounts for its θJA = 32°C/W and 3.9W power dissipation limit at 25°C ambient.

Does MP6601GF-Z require external current sense resistors?

No. MP6601GF-Z uses internal MOSFET R_DS(on)-based current sensing, eliminating external sense resistors. Current regulation is set via the ISET pin resistor (e.g., 71kΩ for 1.0A full-scale), and accuracy is ±5% over temperature for 71–100% scaling ranges.

How does the automatic decay mode function in MP6601GF-Z?

The MP6601GF-Z monitors winding current during fixed off-time. If current remains above threshold at t_OFF end, it initiates fast decay by reversing bridge polarity; once current drops below threshold, it reverts to slow decay. This dual-mode operation maintains precise regulation without manual decay configuration.

What is the purpose of the ROSC pin, and how is it configured?

ROSC sets the constant off-time (t_OFF) of the PWM current regulator. A resistor from ROSC to GND determines t_OFF ≈ 190 × R_t(kΩ) ns - e.g., 200kΩ yields ~23µs. This directly controls switching frequency and current ripple magnitude in the motor winding.

Can MP6601GF-Z drive DC brush motors, and what limitations apply?

Yes - both H-bridges can independently drive DC motors. However, both share the same ISET-defined current limit, so stall current is identical for both motors. Also, short-brake functionality is not supported; coasting occurs when both outputs float.

What thermal layout practices are recommended for MP6601GF-Z in TSSOP-28 EP?

Connect the exposed pad (Pin 28 EP) to a large internal ground plane using ≥6 thermal vias (0.3mm diameter, 0.65mm pitch). Place ISET and ROSC resistors, plus 100nF VIN bypass and 1µF VCP capacitors, within 2mm of respective pins. Avoid routing high-current traces over sensitive analog nodes.

Is MP6601GF-Z compatible with 3.3V-only microcontrollers?

Yes. All logic inputs (APHASE, AI0, AI1, etc.) accept 3.3V-high signals with VIH(min) = 2.1V and feature internal pull-down on nSLEEP. No level-shifting or external biasing is needed - simplifying interface with modern low-voltage MCUs.