Analog Devices Inc./Maxim Integrated MAX1664CUP

Overview

The MAX1664CUP from Maxim Integrated is a highly integrated power management IC for active-matrix TFT-LCD panels, combining a PWM boost converter (DC-DC 1), dual-output PFM converter (DC-DC 2: +28V / –10V), LCD backplane driver (0.35Ω), and phase-locked loop synchronized to BPCLK. It operates from +2.8V to +5.5V input, delivers up to 500mA load current, and features 1MHz nominal switching frequency with ultra-low-noise operation in compact LCD module designs.

For engineers reviewing the MAX1664CUP datasheet, MAX1664CUP pinout, MAX1664CUP application, or MAX1664CUP equivalent, this page provides verified technical context, exact pin functions, confirmed output voltage adjustability (+5.5V / +28V / –10V), real-world efficiency curves, and validated alternative options for AMLCD power supply design.

Technical Context

The MAX1664CUP implements a current-mode PWM architecture for DC-DC 1 (LX1 switch, 0.25Ω typical R_ON) and a synchronized fixed-on-time PFM architecture for DC-DC 2 (LX2P/LX2N switches, 0.9Ω typical R_ON each), enabling independent regulation of positive and negative outputs using a single inductor. Its on-chip PLL locks both converter frequencies to the backplane clock (20–72kHz), with selectable multiplication ratios (16×/24×/32×) yielding 640–1152kHz for DC-DC 1 and 320–576kHz for DC-DC 2.

Startup sequencing is controlled internally: VREF must reach 90% before enabling DC-DC 1; VOUT2– activates only after VOUT1 regulation; VOUT2+ remains at 0V until VOUT2– reaches 90% of target. The open-drain RDY pin asserts high-impedance when all three outputs (VOUT1, VOUT2+, VOUT2–) are within ±10% of regulation, confirming system readiness.

Key Specifications

Pinout & Package

MAX1664CUP is supplied in a 20-pin TSSOP package (1.1mm height), optimized for space-constrained LCD module layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar AMLCD power supply applications.

Compared with MAX1665CUP, the MAX1664CUP trades extended temperature rating for lower unit cost in commercial applications; compared with TPS65105PWPR, it delivers superior noise performance and reduced bill-of-materials through on-chip PLL synchronization and integrated backplane driver.

Availability

MAX1664CUP is available at Aetrix Electronics and suitable for portable LCD modules, industrial HMI panels, automotive infotainment displays, and consumer electronics requiring stable, low-noise AMLCD power supply solutions with minimal external components.

Supply support for MAX1664CUP 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

Maxim Integrated (now part of Analog Devices) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for demanding applications including industrial, automotive, and consumer electronics.

The MAX1664CUP belongs to Maxim's AMLCD power supply product line, designed specifically to integrate TFT-LCD panel power generation, gate driver biasing, and backplane timing into a single compact solution - reducing design time and improving display system reliability.

FAQ

What is the maximum load current supported by the MAX1664CUP's DC-DC 1 output?

The MAX1664CUP's DC-DC 1 output supports up to 500mA continuous load current, as confirmed by the Electrical Characteristics table under "Load Currents Up to 500mA" and validated by efficiency curves showing stable operation at 500mA across input voltages. This rating applies with proper thermal design and recommended 3.3µH inductor (IL1 ≤ 700mA peak). Exceeding this current risks overtemperature shutdown or regulation loss.

Can the MAX1664CUP generate –20V on its negative output without external components?

No, the MAX1664CUP cannot generate –20V on its negative output without external components. Its native VOUT2– range is 0V to –10V, as specified in the General Description and Electrical Characteristics. Achieving –20V requires adding an external inverting charge-pump stage, as detailed in the Applications Information section (Figure 6), which uses additional diodes, capacitors, and careful layout to double the negative voltage magnitude.

How does the MAX1664CUP synchronize its switching frequencies to the backplane clock?

The MAX1664CUP uses an on-chip phase-locked loop (PLL) that multiplies the BPCLK input frequency by 16×, 24×, or 32× (selected via FPLL pin strapping) to generate precise switching clocks for DC-DC 1 and DC-DC 2. This synchronization eliminates beat frequencies and subharmonics, enabling low-EMI operation with ceramic output capacitors. The PLL maintains lock even during brief BPCLK dropouts of more than two cycles.

What is the purpose of the RDY pin on the MAX1664CUP, and how is it used in system design?

The RDY pin on the MAX1664CUP is an open-drain output that signals when all three regulated outputs (VOUT1, VOUT2+, VOUT2–) are within ±10% of their target voltages. In system design, RDY is pulled up externally (e.g., to 3.3V) and connected to a microcontroller's GPIO or reset controller to delay processor initialization until power rails are fully stabilized - preventing erratic behavior during LCD panel power-up.

Does the MAX1664CUP require external MOSFETs for its backplane driver function?

No, the MAX1664CUP does not require external MOSFETs for its backplane driver function. It integrates a complementary N-channel/P-channel pair with 0.35Ω typical on-resistance directly on-die, capable of driving BPCLK-level signals to BPVDD/BPVSS rails. The driver accepts logic-level BPCLK input and outputs high-current transitions to the LCD backplane, eliminating the need for discrete level-shifting transistors or gate drivers.