Renesas MK712SLFTR

Overview

MK712SLFTR from Integrated Device Technology (IDT) is a 4-wire analog resistive touch screen controller IC with integrated 12-bit ratiometric A/D converter, parallel interface, and ultra-low standby current of 0.5 µA (typical at 5.0 V). It continuously monitors touch events, performs X/Y coordinate conversion at up to 197 points/second, stores results in internal registers, and asserts an interrupt signal-enabling direct integration into industrial HMI panels and embedded display systems.

For engineers reviewing the MK712SLFTR datasheet, MK712SLFTR pinout, MK712SLFTR application, or MK712SLFTR equivalent, this page delivers verified technical context-including confirmed 28-pin SOIC package mapping, parallel register interface timing, automotive-grade temperature support (-35°C to +85°C variant available), and real-world design implications of its ratiometric ADC architecture for calibration-free operation.

Technical Context

The MK712SLFTR implements a dedicated analog front-end for 4-wire resistive touch screens, applying voltage across X or Y plates and measuring resulting voltages via a monotonic 12-bit ratiometric ADC. Its conversion rate is programmable via registers 6 and 7, supporting 86–197 points/second depending on configuration.

It uses a parallel 8-bit data bus (D0–D7) with discrete address lines (A0–A2), chip select (CS), read/write strobes (RD/WR), and clock input (CLKIN, 12–20 MHz). The TOUCH output pin signals screen contact state, while INT asserts on valid coordinate capture-cleared only by register read or power-down register write.

Key Specifications

Pinout & Package

Packaged in 28-pin SOIC (300 mil wide body), JEDEC MS-013AC compliant, with 1.27 mm pitch and 17.7–18.4 mm body length. RoHS-compliant Pb-free finish (LF suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar touch screen controller applications.

Compared with TI TSC2007IPW and Microchip AR1021T-I/ML, the MK712SLFTR provides deterministic parallel register access, ratiometric calibration-free operation, and higher maximum sampling rate (197 PPS), making it optimal for deterministic industrial HMIs where register-level control and minimal firmware overhead are prioritized.

Availability

MK712SLFTR is available at Aetrix Electronics and suitable for industrial HMI panels, medical display terminals, and retail kiosk interfaces requiring stable component supply, RoHS compliance, and long-term lifecycle continuity.

Supply support for MK712SLFTR 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

Integrated Device Technology (IDT), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal-path solutions for communications, computing, and industrial markets.

The MK712SLFTR belongs to IDT's legacy touch screen controller product line, designed specifically for cost-sensitive, high-reliability 4-wire resistive touch applications in commercial and industrial displays-prioritizing low power, minimal external components, and software compatibility with existing Gazelle-based drivers.

FAQ

What is the primary function of the MK712SLFTR in a touch-enabled system?

The MK712SLFTR serves as a dedicated 4-wire analog resistive touch screen controller IC. It drives the X and Y electrode plates, performs ratiometric 12-bit analog-to-digital conversion of touch coordinates, stores X/Y values in internal registers, and asserts an interrupt signal (INT) to notify the host processor. Its design eliminates the need for external transistors or calibration routines in many applications, and the MK712SLFTR operates with ultra-low standby current (0.5 µA typical) to extend battery life in portable HMIs.

Does the MK712SLFTR support both 3.3 V and 5 V supply rails?

Yes, the MK712SLFTR supports dual-supply operation: VDD may be either 3.3 V or 5 V, with specified operating ranges of 3.0–5.5 V (commercial/industrial) and 3.135–5.5 V (automotive). All VDD pins (pins 4, 5, and 22) must be connected to the same voltage rail, and appropriate decoupling capacitors are required per the datasheet layout recommendations. The MK712SLFTR's I/O thresholds scale accordingly-VIH is 1.9 V at 3.3 V supply and 2.0 V at 5 V supply-ensuring robust logic-level compatibility.

How does the ratiometric ADC in the MK712SLFTR improve system calibration requirements?

The MK712SLFTR's 12-bit ratiometric ADC defines full-scale (4095) based on the actual voltage applied across the touch screen electrodes-not a fixed internal reference. This makes coordinate measurements largely independent of variations in screen resistance, temperature, and supply voltage drift. As a result, the MK712SLFTR can often eliminate factory or runtime calibration steps, especially in stable mechanical assemblies. However, parasitic interconnect resistance accounts for ~20% of total screen resistance, rendering the outer ~10% of full-scale range inaccessible-a known design constraint of the MK712SLFTR's architecture.

What is the role of the TOUCH pin (pin 3) on the MK712SLFTR?

The TOUCH pin (pin 3) is a dedicated open-drain output that signals physical screen contact state: it goes low when the screen is touched and high when untouched. Unlike the INT pin-which asserts only after successful X/Y coordinate conversion-the TOUCH pin responds immediately to plate closure, enabling hardware-level debounce and fast wake-up decisions without CPU intervention. This behavior is intrinsic to the MK712SLFTR's analog sensing architecture and is unaffected by register configuration or conversion rate settings.

Can the MK712SLFTR be used with a switching regulator power supply?

The MK712SLFTR can be powered from a switching regulator, but screen conversions must not occur while the regulator is in burst-mode or other low-power noise-generating states. As documented in the datasheet, such modes introduce power supply noise that causes spurious coordinate readings. To ensure accuracy, the MK712SLFTR's conversion activity should be synchronized to periods when the regulator operates in continuous conduction mode-or the regulator's low-power mode must be disabled during touch acquisition. This requirement applies specifically to the MK712SLFTR's sensitive analog measurement path and is not mitigated by standard decoupling alone.