Texas Instruments CSD86336Q3D

Overview

CSD86336Q3D from Texas Instruments is a synchronous buck NexFET™ power block integrating optimized control and sync MOSFETs in a single 3.3-mm × 3.3-mm SON package. It delivers 93.0% system efficiency at 12 A, supports up to 20-A operation, and is engineered for 5-V gate drive with effective AC on-impedance of 9.1 mΩ (HS) and 3.4 mΩ (LS) at 20 A/500 kHz - enabling high-density POL DC-DC conversion in CPU/GPU VRM applications.

For engineers reviewing the CSD86336Q3D datasheet, CSD86336Q3D pinout, CSD86336Q3D application, or CSD86336Q3D equivalent, key selection criteria include measured ZDS(on) under real switching conditions, thermal resistance (RθJC = 3.2°C/W to PGND), SOA compliance at 125°C junction, and compatibility with 5-V PWM controllers in multiphase buck topologies.

Technical Context

The CSD86336Q3D implements a half-bridge power block architecture with parametrically tuned N-channel control and sync FETs sharing ultra-low-inductance internal interconnects. Its patented packaging eliminates common-source inductance (CSI), directly reducing Qgd-related switching losses and enabling stable operation up to 1.5 MHz.

It operates with 4.5–8 V gate drive, requires external bootstrap capacitor (CBOOT = 0.1 µF min), and relies on an external PWM controller for phase control. Thermal performance is defined by dual RθJC paths: 17°C/W (top) and 3.2°C/W (PGND pin), with RθJA ranging 55–105°C/W depending on PCB copper area.

Key Specifications

Pinout & Package

Package: SON 3.3-mm × 3.3-mm plastic package with exposed thermal pad (PGND) on bottom surface. Pin 9 is PGND and serves as primary thermal and electrical reference.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck power block applications.

Compared with CSD86336Q3D, CSD86350Q5D offers lower ZDS(on) and higher current headroom at the cost of increased gate charge and thermal demand, while MP2960GQ trades external control flexibility for integration simplicity - making CSD86336Q3D optimal for scalable, high-frequency, controller-based POL designs.

Availability

CSD86336Q3D is available at Aetrix Electronics and suitable for server VRM, GPU power delivery, AI accelerator POL, and industrial FPGA core rail applications requiring stable component supply, long-lifecycle support, and verified thermal performance up to 125°C junction temperature.

Supply support for CSD86336Q3D 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

Texas Instruments is a global semiconductor company specializing in analog, embedded processing, and power management technologies with over 50 years of power conversion innovation.

The CSD86336Q3D belongs to TI's NexFET™ power block product line, designed specifically to replace discrete MOSFET pairs in high-frequency, high-current synchronous buck converters - prioritizing system-level efficiency, thermal density, and layout simplicity over standalone device metrics.

FAQ

What is the maximum recommended switching frequency for CSD86336Q3D?

The CSD86336Q3D is rated for operation up to 1500 kHz under recommended conditions (VGS = 4.5–8 V, adequate gate drive strength, and proper layout). At 1500 kHz, normalized power loss increases ~1.4× versus 500 kHz, so thermal design must account for higher dissipation. The CSD86336Q3D data sheet provides normalized curves to adjust SOA and loss for any fSW between 150–1500 kHz.

Does CSD86336Q3D require an external bootstrap capacitor, and what value is recommended?

Yes, CSD86336Q3D requires an external bootstrap capacitor connected between BOOT and PGND. Texas Instruments specifies a minimum value of 0.1 µF (e.g., 0603 ceramic) placed as close as possible to the BOOT and PGND pins. This capacitor supplies gate drive energy for the high-side FET during each switching cycle and must have low ESR to sustain 5-V gate drive under 20-A load conditions.

How does the effective AC on-impedance (ZDS(on)) of CSD86336Q3D differ from traditional RDS(on)?

ZDS(on) for CSD86336Q3D (9.1 mΩ HS / 3.4 mΩ LS) is measured under real switching conditions (VIN = 12 V, VGS = 5 V, IOUT = 20 A, fSW = 500 kHz), incorporating package parasitics and dynamic effects. Traditional RDS(on) is a DC measurement that ignores CSI and AC losses. Because CSD86336Q3D's patented packaging eliminates CSI, its ZDS(on) reflects actual in-circuit conduction loss - making it a more accurate predictor of system efficiency than RDS(on).

Can CSD86336Q3D be used in multiphase buck configurations, and what layout considerations apply?

Yes, CSD86336Q3D is explicitly designed for multiphase synchronous buck converters. Layout requires strict matching of VIN, VSW, and PGND paths across phases to ensure current sharing. Each CSD86336Q3D must have dedicated 0.1 µF BOOT capacitors and ≥40 µF total VIN bypass capacitance. Critical: minimize loop area between TG/TGR and BG pins and their respective gate drivers to preserve phase alignment and reduce EMI.

What thermal interface materials or PCB practices maximize heat dissipation for CSD86336Q3D?

To maximize heat dissipation, solder the exposed PGND pad (Pin 9) to a minimum 1-in² (6.45 cm²) 2-oz copper area on the PCB - achieving RθJA = 55°C/W. Use thermal vias (≥8× 12-mil) under the pad connected to inner-layer ground planes. Avoid solder mask over the thermal pad. For high-reliability applications, TI recommends NiAu or ENIG finish and IPC-A-610 Class 2/3 compliant reflow profiling to ensure void-free solder joints beneath the package.