STMicroelectronics ST8024LTR

Overview

ST8024LTR from STMicroelectronics is a smartcard interface IC designed for ISO 7816/GSM11.11/EMV 4.2-compliant systems, providing regulated 1.8 V ±6.5% card supply (VCC), three protected half-duplex I/O lines (C4/C7/C8), integrated 26 MHz crystal oscillator, and hardware-controlled activation/deactivation sequences. It operates over –25 to 85 °C in TSSOP-20 package and supports set-top box conditional access readers.

For engineers reviewing the ST8024LTR datasheet, ST8024LTR pinout, ST8024LTR application, or ST8024LTR equivalent, key selection criteria include VCC regulation accuracy (±6.5% at 1.8 V), thermal/short-circuit protection on all card contacts, non-inverted RST control via RSTIN, and compatibility with NDS conditional access systems (excluding ST8024LTR variant).

Technical Context

The ST8024LTR integrates a step-up converter powered by VDDP (4.75–6.5 V) to generate tightly regulated VCC (1.8 V ±6.5%, 3 V, or 5 V) with slew rate control (0.08–0.22 V/µs) and overload detection (~120 mA). Its clock circuitry delivers up to 20 MHz to the card via CLK, programmable by CLKDIV1/CLKDIV2 (÷1, ÷2, ÷4, ÷8) with synchronous frequency changes.

It features dual card presence inputs (PRES active low, PRES active high), multiplexed OFF interrupt output, and built-in debounce on card presence signals. The device implements automatic hardware-triggered deactivation on short-circuit, card removal, overheating, or VDD/VDDP dropout - all without MCU intervention.

Key Specifications

Pinout & Package

TSSOP-20 package with 0.65 mm lead pitch, 7.0 mm × 4.4 mm body, and exposed thermal pad (not electrically connected). Pin 1 marked by notch or dot; pin numbering counterclockwise from top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar smartcard interface applications.

Compared with ST8024LTR, ST8024LCTR offers extended configurability at the cost of size, while ST8024LCDR trades miniaturization for manufacturability - making ST8024LTR optimal for space-constrained, 1.8 V–focused designs like modern CAM modules.

Availability

ST8024LTR is available at Aetrix Electronics and suitable for smartcard readers for set-top boxes, IC card readers for banking, and identification/pay TV terminals requiring stable component supply across industrial temperature ranges and long product lifecycles.

Supply support for ST8024LTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, analog ICs, and smart power solutions for automotive, industrial, and consumer markets.

The ST8024L series targets secure smartcard infrastructure, delivering integrated analog interface functionality to replace multi-component solutions in ISO 7816-compliant readers with minimal external parts.

FAQ

What is the maximum card supply current supported by ST8024LTR at 1.8 V?

The ST8024LTR delivers up to 45 mA continuous current at 1.8 V VCC, with short-circuit protection activating at ~120 mA. This meets EMV 4.2 Class C card requirements and supports transient spikes up to 100 mA for ≤2 µs, verified per Table 8 electrical characteristics.

Can ST8024LTR operate without an external crystal?

Yes - ST8024LTR includes a fully integrated 26 MHz oscillator. When XTAL2 is left open, the internal oscillator drives CLK generation. External crystals (2–26 MHz) are optional and connected between XTAL1 and XTAL2 only if higher timing precision or frequency flexibility is required.

How does the 1.8V pin override the 5V/3V pin setting?

When the 1.8V pin is driven high, the device forces 1.8 V VCC output regardless of the 5V/3V pin state. This is hardwired logic within the VCC selection block (Table 23), ensuring deterministic low-voltage operation without software coordination or timing dependencies.

Is thermal protection active on all card contact pins?

Yes - thermal and short-circuit protection is implemented on all five card contact pins: RST (C2), CLK (C3), AUX1 (C4), I/O (C7), and AUX2 (C8). Each path includes independent current limiting and thermal foldback, as confirmed in Section 6.10 "Fault detection" and Table 19.