NXP Semiconductors SDIO101IHR,551

Overview

SDIO101IHR,551 from NXP Semiconductors is an SD/SDIO/MMC/CE-ATA host controller IC with a 16-bit asynchronous memory interface, supporting full-speed (<25 MHz) and high-speed (<52 MHz) data transfers, 1.8 V core supply, and dual-voltage SD port operation (1.8 V–3.3 V). It integrates a 2 kB double-data buffer, on-board PLL with fractional clock divider, and five power-saving modes including Hibernate and Coma for embedded microprocessor systems requiring robust removable storage interfacing.

For engineers reviewing the SDIO101IHR,551 datasheet, SDIO101IHR,551 pinout, SDIO101IHR,551 application, or SDIO101IHR,551 equivalent, key selection considerations include its HXQFN60U package, SD Host Standard v2.0 compliance, DMA-capable slave interface, programmable SDCLK drive strength, and dedicated SD card detection/write-protection inputs - all critical for low-power, high-reliability host controller integration in resource-constrained designs.

Technical Context

The SDIO101IHR,551 implements the full SD Host Standard Specification v2.0 register set (including Present State, Power Control, and Capabilities registers), extended with four proprietary registers (IO Configuration at 0x50, DMA at 0xF4, Secondary Clock Control at 0xF6, Miscellaneous at 0xF8) for fine-grained control of SDCLK drive strength, DREQ timing, fractional clock division, and ultra-low-power mode activation. Its PLL (0xFA) generates base SD clocks from X1_CLK, then combines standard and fractional dividers to achieve precise SDCLK frequencies up to 52 MHz.

It supports 1-bit/4-bit SD/SDIO and 8-bit MMC/CE-ATA transactions, with separate voltage domains: VDD = 1.8 V (core), VDDA = 1.8 V (analog), VDD(IO) = 2.5–3.3 V (host interface), and VDD(SD) = 1.8–3.3 V (card interface). The 2 kB buffer enables efficient interrupt or DMA-based transfers, while POW[1:0] outputs allow software-controlled external SD power switching between 1.8 V (low-power) and 3.3 V (normal) modes per Table 4.

Key Specifications

Pinout & Package

SDIO101IHR,551 is housed in a 5 mm × 5 mm × 0.5 mm HXQFN60U (SOT1133-1) thermally enhanced quad flat no-lead package with 60 terminals and an exposed center pad requiring PCB thermal vias for optimal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SD/SDIO/MMC host controller applications.

Compared with AS3722-SDIO and TCM2000-SD, SDIO101IHR,551 provides the only combination of SD Host Standard v2.0 compliance, fractional SDCLK tuning, dedicated hardware card-detect logic, and five-tier power management - making it the sole choice for new designs requiring interoperability with SDIO 2.0 peripherals, CE-ATA storage, and battery-sensitive operation.

Availability

SDIO101IHR,551 is available at Aetrix Electronics and suitable for smartphone baseband expansion, industrial HMI storage, medical diagnostic imaging, automotive infotainment, and portable test equipment requiring stable component supply across long production lifecycles.

Supply support for SDIO101IHR,551 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

NXP Semiconductors is a global semiconductor company specializing in secure connectivity solutions for automotive, industrial, and consumer applications, with leadership in interface, power management, and MCU technologies.

The SDIO101IHR,551 belongs to NXP's SD/SDIO/MMC host controller product line, designed specifically to enable seamless, standards-compliant removable storage integration into resource-constrained microprocessor systems - emphasizing low power, flexible voltage operation, and hardware-accelerated protocol handling.

FAQ

What is the primary function of the SDIO101IHR,551 in a system architecture?

The SDIO101IHR,551 serves as a dedicated SD/SDIO/MMC/CE-ATA physical-layer host controller, bridging a microprocessor's 16-bit asynchronous memory bus to removable storage devices. It handles command/response protocol, data transfer timing, CRC generation/checking, and power management - allowing standard SDIO driver stacks to operate without modification. Its role is strictly host-side protocol management, not card-side functionality.

Does the SDIO101IHR,551 support both SDIO 1.00 and SDIO 2.00 specifications?

Yes, the SDIO101IHR,551 explicitly supports SDIO Card Specification version 2.00 per Section 2.1 of its datasheet. It implements Multi-block, Suspend/Resume, Read Wait, and Wake-up Control features defined in that revision. SDIO 1.00 compatibility is inherent through backward-compatible command sets and timing, but official validation and feature support are documented only for v2.00.

How does the fractional clock divider (0xF6 register) improve SD clock accuracy in the SDIO101IHR,551?

The fractional clock divider in the SDIO101IHR,551 uses an 8-bit integer (N) and 4-bit fractional (M) component to fine-tune SDCLK frequency beyond what the standard PLL + integer divider can achieve. For example, with a 13 MHz X1_CLK input, it enables precise derivation of 48.9 MHz (vs. coarse 52 MHz or 45.5 MHz), reducing SD bus timing margin violations and improving interoperability with high-speed SD cards.

Can the SDIO101IHR,551 operate with a 1.8 V SD card supply while the host interface runs at 3.3 V?

Yes, the SDIO101IHR,551 supports independent voltage domains: VDD(SD) pins (D6/B8/D7) accept 1.8–3.3 V for the SD/SDIO/MMC/CE-ATA interface, while VDD(IO) pins (B12/B16/A3) accept 2.5–3.3 V for the 16-bit host bus. This isolation allows simultaneous 1.8 V SD card operation and 3.3 V microprocessor interfacing - confirmed by Table 2 pin descriptions and Section 2.1 voltage specifications.

What are the functional differences between Hibernate mode and Coma mode in the SDIO101IHR,551?

Hibernate mode (enabled via bit 0 of 0xF8) switches off the on-board oscillator, PLL, and data buffer memories - retaining only minimal state for fast wake-up. Coma mode (bit 1 of 0xF8) internally disconnects supply power to most of the chip, achieving deeper power savings than Hibernate. Both are distinct from Standby (bit 0 of 0x2C) and require explicit register writes to activate - detailed in Section 2.1 and 6.4.4.