Monolithic Power Systems Inc. MP161AGS-33-P

Overview

MP161AGS-33-P from Monolithic Power Systems is an integrated power solution combining a 700V switching regulator, a 3.3V low-dropout linear regulator, and two 2Ω relay drivers in a single SOIC-16 package. It delivers 12V/70mA and 3.3V/50mA outputs with ultra-low standby power via STBY-controlled voltage reduction to 5.7V, enabling energy-efficient home automation control panels requiring relay actuation and MCU biasing.

For engineers reviewing the MP161AGS-33-P datasheet, MP161AGS-33-P pinout, MP161AGS-33-P application, or MP161AGS-33-P equivalent, key selection criteria include its 17Ω HV MOSFET R_DS(ON), 240mA peak current limit, integrated freewheeling diodes for relay coils, and dual-rail regulation architecture supporting both active and standby operating modes.

Technical Context

The MP161AGS-33-P implements constant-voltage (CV) regulation using internal loop compensation with feedback referenced to SOURCE, where V_REF = 1.225V sets output via external resistor divider or fixed 12V output. Its 700V HV MOSFET operates with programmable t_minoff (9.5μs) and t_maxon (25μs) timing constraints to enforce CCM/DCM boundary control and prevent brown-out under light load.

The integrated LDO accepts up to 30V input and delivers a fixed 3.3V ±2% output with 300mV dropout at 50mA, while the dual relay drivers feature rail-to-rail 30V capability, 100ns turn-off delay, and internal pull-down resistors ensuring fail-safe off-state behavior without external biasing.

Key Specifications

Pinout & Package

MP161AGS-33-P is housed in a 16-pin SOIC package with exposed pad (SOIC-16), optimized for surface-mount assembly and thermal dissipation in compact industrial control modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar integrated power management applications.

Compared with MP161BGS-33, the MP161AGS-33-P trades 180mA peak current headroom for tighter R_DS(ON) tolerance and lower system cost, while the MPQ161AGS-33-P adds qualification overhead irrelevant to non-automotive use cases-making MP161AGS-33-P the optimal choice for cost-sensitive, thermally constrained home/industrial controllers.

Availability

MP161AGS-33-P is available at Aetrix Electronics and suitable for smart lighting control panels, industrial PLC I/O modules, home appliance mainboards, and energy monitoring gateways requiring stable component supply across multi-year production cycles.

Supply support for MP161AGS-33-P 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 expertise in DC/DC conversion, motor drivers, and integrated power solutions.

The MP161 product line was designed specifically for space-constrained, relay-based control systems in home and industrial automation, integrating HV switching, LDO regulation, and driver stages to eliminate discrete power tree components.

FAQ

What is the maximum allowable input voltage on the DRAIN pin?

The absolute maximum DRAIN-to-SOURCE voltage is 700V, with guaranteed operation up to 400V DRAIN leakage current (17μA typical). Operation above 400V increases leakage but remains within safe operating area as long as power dissipation stays below 1.56W at 25°C ambient. Thermal design must account for increased R_DS(ON) at elevated temperatures.

Can the MP161AGS-33-P drive relays directly without external flyback diodes?

Yes-the device integrates freewheeling diodes for both OUTA and OUTB channels, allowing direct connection to standard 12V relay coils. Each diode has a 1V forward drop at 100mA, eliminating the need for external suppression components and reducing PCB footprint by up to 4 passive devices per channel.

How does standby mode affect the LDO output voltage?

Standby mode only reduces the switching regulator's VCC output from 12V to 5.7V; the LDO output remains fixed at 3.3V regardless of STBY state. Since VIN (LDO input) is typically connected to VCC, designers must ensure the 5.7V standby rail still exceeds the LDO's 3.9V UVLO threshold to maintain uninterrupted 3.3V supply.

What is the purpose of the NC pins (6, 7, 12) in the SOIC-16 package?

Pins 6, 7, and 12 are no-connect terminals with no internal bonding or electrical function. They must remain unconnected in PCB layout; routing traces or placing vias on these pads may cause mechanical stress or solder bridging. Their presence maintains package symmetry for automated assembly and thermal uniformity during reflow.

Does the MP161AGS-33-P support adjustable output voltage via the FB pin?

Yes-connecting an external resistor divider between VCC and FB overrides the internal 450kΩ/4.1MΩ network, enabling precise output voltage setting using Equation (1): V_O = V_REF × (1 + R_UP/R_LOW). The internal divider remains active but is paralleled by lower-value external resistors, ensuring stable regulation down to 5V or up to 24V depending on component selection.

What protections activate during a short circuit on the LDO output?

The LDO implements independent over-temperature protection (OTP) but no current-limiting or short-circuit shutdown. A sustained short on VO will cause localized heating until junction temperature reaches 150°C, triggering global OTP that disables all functions-including switching regulator and relay drivers-until thermal recovery hysteresis (30°C) is met.

Is the MP161AGS-33-P RoHS-compliant and halogen-free?

Yes-MP161AGS-33-P is lead-free, halogen-free, and fully compliant with EU RoHS Directive 2011/65/EU. MPS confirms green status through its Quality Assurance portal, with material declarations available upon request for IPC-1752-compliant supply chain reporting.