Monolithic Power Systems Inc. MP5099GDT-Z

Overview

MP5099GDT-Z from Monolithic Power Systems is a dual-channel e-fuse IC providing integrated current limiting, over-voltage protection, reverse current blocking (on 5V channel), and analog current monitoring for 12V and 5V power rails. It features 40mΩ R_DS(ON), fixed 4A/2.95A (CH1) and 3A/2.2A (CH2) trip/hold current limits, and 2µs OVP response - deployed in SSD/HDD hot-swap power distribution.

For engineers reviewing the MP5099GDT-Z datasheet, MP5099GDT-Z pinout, MP5099GDT-Z application, or MP5099GDT-Z equivalent, key selection criteria include dual-rail surge tolerance (24V/100ms on CH1, 16V/100ms on CH2), independent soft-start control via SS1/SS2 pins, IMON_SEL–based channel-selectable current monitoring, and latch-off thermal shutdown at 150°C.

Technical Context

The MP5099GDT-Z integrates two independent high-side current-limit switches with dedicated UVLO (8.5V/4.0V), OVP (15V/5.7V), and hiccup-mode OCP (2ms on, 200ms off). Each channel employs fast-turnoff circuitry for sub-1µs short-circuit response and uses internal charge pumps to drive MOSFET gates without external bias.

Current monitoring is implemented via proportional IMON output (28μA/A typical gain) with selectable channel routing through IMON_SEL, while soft-start timing is set by external CSS capacitors (12ms default when floating). Reverse current protection is active only on the 5V channel, with no reverse blocking on the 12V rail.

Key Specifications

Pinout & Package

MP5099GDT-Z is housed in a TQFN-10 (2mm × 3mm) package with exposed thermal pad, optimized for space-constrained hot-swap modules and storage subsystems. Pin numbering follows JEDEC MO-220 standard with Pin 1 marked by index area.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-rail e-fuse applications.

Compared with TPS25942LARVRR and RTQ2134BGQW, MP5099GDT-Z uniquely delivers matched 12V/5V channel performance with integrated current monitoring, reverse blocking on the low-voltage rail, and sub-2µs OVP - making it optimal for compact, telemetry-enabled storage and industrial hot-swap designs.

Availability

MP5099GDT-Z is available at Aetrix Electronics and suitable for hard disk drives, solid-state drives, and industrial backplane power distribution requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP5099GDT-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 power management ICs, with core expertise in DC/DC converters, e-fuses, and motor drivers.

The MP5099 belongs to MPS's E-Fuse & Load Switch product line, engineered specifically for robust hot-swap, inrush control, and fault telemetry in data center storage, industrial automation, and embedded computing platforms.

FAQ

What is the maximum continuous input voltage rating for each channel?

VIN1 supports 10.8V to 13.2V continuous operation with 24V/100ms surge tolerance; VIN2 supports 4.5V to 5.5V continuous operation with 16V/100ms surge tolerance. Absolute maximum ratings are +22V (VIN1/VOUT1) and +15V (VIN2/VOUT2), but sustained operation above recommended ranges risks reliability degradation and invalidates warranty conditions.

How does the IMON pin function with IMON_SEL, and what resistor value is recommended?

IMON outputs a current proportional to the selected channel's load current: pull IMON_SEL high for CH1 (28μA/A), float or pull low for CH2 (29μA/A). With R_IMON = 24.9kΩ, V_IMON reaches ~2.15V at 4A (CH1) or ~1.88V at 3A (CH2), staying within 0–2.4V linear range. Lower resistors reduce sensitivity but improve noise immunity.

Does MP5099GDT-Z provide reverse current protection on both channels?

No - reverse current blocking is implemented only on the 5V channel (VIN2→VOUT2 path). The 12V channel (VIN1→VOUT1) allows bidirectional current flow. This architecture matches typical backplane use cases where 5V auxiliary rails require backfeed prevention, but main 12V rails do not.

What happens during a short-circuit event, and how quickly does protection activate?

Upon short detection, MP5099GDT-Z triggers fast turn-off (<1µs) using secondary 8A current limit, then enters hiccup mode: 2ms active current limiting followed by 200ms shutdown. This cycle repeats until fault clears. Unlike latch-off devices, hiccup mode preserves system awareness and enables automatic recovery without manual reset.

Can soft-start time be adjusted independently for each channel?

Yes - SS1 and SS2 are separate pins, each sinking ~4.8µA to charge their respective CSS capacitors. Using different CSS values (e.g., 100nF on SS1, 220nF on SS2) yields distinct t_SS per channel, enabling sequenced power-up essential for storage controllers with strict voltage ramp order requirements.

Is thermal shutdown latched or auto-recovering?

Thermal shutdown is latch-off: once junction temperature exceeds 150°C, both channels disable permanently until power is cycled (VIN removed and reapplied). This prevents thermal runaway but requires system-level reset logic - unlike hiccup-mode OCP, no automatic retry occurs after cooling.

What PCB layout practices maximize thermal performance?

Connect VIN/VOUT pads directly to large copper planes; place 10µF input capacitors within 3mm of VIN/GND pins; route SS traces away from noisy signals; and solder the exposed thermal pad to a dedicated inner-layer ground plane using ≥6 thermal vias (0.3mm diameter). These steps maintain θ_JA near 40°C/W per datasheet EV5099-D-00A reference board.