Diodes Incorporated PAM8904QJER

Overview

PAM8904QJER from Diodes Incorporated is an AEC-Q100 Grade 2 qualified piezo sounder driver IC that delivers 18VPP differential output from a 3V supply using an integrated 1.0MHz fixed-frequency charge pump (1x/2x/3x modes), supports 20Hz–300kHz input signals, and features auto-standby, overtemperature shutdown, and short-circuit protection for automotive alarm and EV approach warning systems.

For engineers reviewing the PAM8904QJER datasheet, PAM8904QJER pinout, PAM8904QJER application, or PAM8904QJER equivalent, this page provides verified technical context on boost mode selection, differential vs. single-ended output configuration, thermal protection hysteresis (+37°C), and AEC-Q100-compliant supply sequencing requirements.

Technical Context

The PAM8904QJER implements a dual-capacitor switched-capacitor charge pump with programmable gain (1x/2x/3x) controlled by CPM1/CPM2 logic inputs, enabling VOUT generation up to 9V from 2.3–5.0V VIN. Its output stage drives ceramic piezo elements differentially across VO1/VO2 or single-endedly via VO1 with VO2 open.

Internal protection includes non-latching short-circuit current limiting (40mA max), junction temperature monitoring with +150°C shutdown and +37°C hysteresis, and automatic transition to <1µA shutdown current when DIN remains inactive for 42ms - all operating within -40°C to +105°C ambient range.

Key Specifications

Pinout & Package

Package: U-QFN3030-16 (Type B), 3.0mm × 3.0mm × 0.6mm body, 0.5mm pitch, exposed thermal pad (recommended GND connection).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar piezo sounder driver applications.

Compared with TPS61178 and BD7840FS, the PAM8904QJER uniquely integrates full piezo drive functionality-including programmable gain, differential outputs, auto-standby, and automotive-grade protection-in a single AEC-Q100-qualified chip, eliminating external components and firmware coordination overhead.

Availability

PAM8904QJER is available at Aetrix Electronics and suitable for automotive alarm systems, EV approach warning modules, and dashboard audio alert circuits requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for PAM8904QJER 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

Diodes Incorporated is a global semiconductor manufacturer specializing in discrete, analog, and mixed-signal solutions for automotive, industrial, and consumer markets.

The PAM8904QJER belongs to Diodes' automotive-qualified piezo driver product line, engineered specifically for high-reliability, low-power acoustic signaling in safety-critical vehicle subsystems.

FAQ

What charge pump modes does the PAM8904QJER support, and how are they selected?

The PAM8904QJER supports 1x, 2x, and 3x charge pump modes plus forced shutdown, selected via logic levels on CPM1 and CPM2 pins. Valid combinations are (CPM1,CPM2) = (0,1) for 1x, (1,0) for 2x, (1,1) for 3x, and (0,0) or (1,0) with DIN = 0 for shutdown. The 3x mode is restricted to VIN ≤ 3.9V to avoid exceeding the 12V VOUT absolute maximum rating.

How does the auto-standby feature operate, and what is its timing behavior?

Auto-standby activates after 42ms of no valid signal on DIN, reducing supply current to ≤1µA. Wake-up occurs within 270–350µs of the next DIN high pulse, depending on charge pump mode (1x fastest, 3x slowest). This timing is measured from DIN edge to 90% of final VOUT level and is guaranteed across -40°C to +105°C.

Can the PAM8904QJER drive both differential and single-ended piezo loads, and what are the configuration requirements?

Yes - for differential drive, connect the piezo element between VO1 and VO2; for single-ended, connect one terminal to VO1 and the other to GND while leaving VO2 unconnected. The internal driver topology supports both configurations without external component changes, though output voltage swing is halved in single-ended mode (9VPP vs. 18VPP).

What protection mechanisms are built into the PAM8904QJER, and how do they respond to faults?

The PAM8904QJER includes overtemperature shutdown (trip at +150°C, recover at +113°C), non-latching short-circuit current limiting (40mA max), and input overvoltage protection (VIN absolute max = +5.5V). All protections operate autonomously without external circuitry; thermal shutdown disables both charge pump and outputs, while short-circuit limiting allows immediate recovery upon fault removal.