Analog Devices Inc./Maxim Integrated MAX16903SATB33/V+T

Overview

The MAX16903SATB33/V+T from Maxim Integrated is a synchronous buck DC-DC converter IC delivering 1A output at fixed 3.3V, operating from +3.5V to +28V input with 25μA quiescent current in skip mode, 2.1MHz switching frequency, and AEC-Q100 qualification for automotive power rail generation.

For engineers reviewing the MAX16903SATB33/V+T datasheet, MAX16903SATB33/V+T pinout, MAX16903SATB33/V+T application, or MAX16903SATB33/V+T equivalent, this page provides verified technical context, package mapping, thermal performance data, spread-spectrum EMI reduction capability, and automotive-grade reliability specifications directly extracted from Maxim's official documentation.

Technical Context

The MAX16903SATB33/V+T implements current-mode control with integrated high-side (400–800mΩ R_DS(ON)) and low-side (250–450mΩ R_DS(ON)) MOSFETs, enabling dropout operation up to 97% duty cycle. It features internal soft-start (8ms typical), programmable SYNC input for forced PWM, skip mode, or external clock synchronization, and undervoltage lockout (3.0V typical).

Its spread-spectrum option modulates frequency by +6% around 2.1MHz to reduce radiated EMI while maintaining AM-band immunity. The device monitors output voltage quality via open-drain PGOOD (91–94% falling threshold) and supports cold-crank operation down to 3.5V input with transient tolerance to +42V.

Key Specifications

Pinout & Package

MAX16903SATB33/V+T is housed in a thermally enhanced 10-pin TDFN-EP package (3mm × 3mm × 0.75mm) with exposed pad soldered to PGND for optimal thermal dissipation (θ_JA = 41°C/W, θ_JC = 9°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck converter applications.

Compared with LM61480QWRNXTQ1 and TPS62933QWRVRRQ1, the MAX16903SATB33/V+T offers tighter cold-crank operation (down to 3.5V), lower quiescent current (25μA vs. ~40μA), and factory-enabled spread-spectrum-making it uniquely suited for cost-sensitive, space-constrained automotive modules requiring robust low-I_Q performance and certified EMI reduction.

Availability

MAX16903SATB33/V+T is available at Aetrix Electronics and suitable for automotive infotainment systems, ADAS camera modules, and body control units requiring stable component supply with AEC-Q100 compliance, extended temperature operation, and low-quiescent-current performance.

Supply support for MAX16903SATB33/V+T 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, designs precision analog, mixed-signal, and power management ICs for automotive, industrial, and communications applications.

The MAX16903 series is a family of high-voltage, low-I_Q synchronous buck converters engineered specifically for automotive power rails where cold-crank resilience, EMI control, and AEC-Q100 reliability are mandatory.

FAQ

What is the maximum input voltage the MAX16903SATB33/V+T can withstand without damage?

The MAX16903SATB33/V+T has an absolute maximum input voltage rating of +42V for transient conditions such as load dump, while its continuous operating range is +3.5V to +28V. This ensures survival during automotive battery transients without requiring external clamping circuitry. The device remains functional throughout cold-crank events down to 3.5V input, and its internal protection circuits prevent latch-up or permanent damage at +42V for short durations. MAX16903SATB33/V+T's robust input stage eliminates the need for external TVS diodes in many automotive designs.

Does the MAX16903SATB33/V+T require external compensation components?

No, the MAX16903SATB33/V+T uses current-mode control architecture with internal compensation, eliminating the need for external resistors or capacitors on the feedback loop. Its fixed 3.3V output version is factory-trimmed for stability across the full -40°C to +125°C temperature range and 0–1A load. The device achieves phase margin >45° and gain margin >10dB with standard 10µF ceramic output capacitance, simplifying design and reducing bill-of-materials cost. MAX16903SATB33/V+T's self-contained regulation removes tuning effort typically required for adjustable buck controllers.

How does the spread-spectrum feature of the MAX16903SATB33/V+T reduce EMI?

The MAX16903SATB33/V+T's spread-spectrum function modulates its 2.1MHz switching frequency by +6% (i.e., 2.1MHz to 2.226MHz) using a deterministic dither pattern, spreading radiated energy across a bandwidth instead of concentrating it at a single fundamental frequency. This reduces peak emissions by up to 10dB, helping systems meet CISPR 25 Class 5 requirements without adding ferrite beads or metal shielding. The modulation is disabled during external SYNC operation and only active when the internal oscillator runs. MAX16903SATB33/V+T's implementation guarantees the frequency never drops into the AM radio band (1.8MHz), preserving immunity.

What is the purpose of the BIAS pin on the MAX16903SATB33/V+T?

The BIAS pin on the MAX16903SATB33/V+T provides a regulated +5V internal supply for the IC's logic and control circuitry, derived from the main SUP input. It must be bypassed with a 2.2µF ceramic capacitor to GND to stabilize the internal LDO and prevent noise coupling into sensitive analog blocks. During normal operation, BIAS supplies current to the error amplifier, oscillator, and gate drivers. In skip mode, BIAS remains active to maintain regulation while most other circuitry powers down-enabling the 25μA quiescent current. MAX16903SATB33/V+T's BIAS pin also serves as a sync reference level for forced PWM mode when connected to the SYNC pin.

Can the MAX16903SATB33/V+T operate in dropout, and what is its minimum on-time?

Yes, the MAX16903SATB33/V+T operates in dropout by achieving up to 97% duty cycle, maintaining regulation even when input voltage approaches the output voltage (e.g., 3.5V input for 3.3V output). To sustain gate drive for the high-side FET in dropout, the device periodically turns off the high-side switch for ~150ns every 6.5μs to recharge the BST capacitor, resulting in an effective switching frequency of ~150kHz. Its minimum on-time is 80ns (typical), which determines the lowest achievable duty cycle at high input voltages. MAX16903SATB33/V+T's dropout behavior is fully specified and tested across temperature, ensuring predictable performance during automotive cold-crank conditions.