STMicroelectronics ST8024LCDR

Overview

ST8024LCDR from STMicroelectronics is a smartcard interface IC designed for ISO 7816/GSM11.11/EMV 4.2-compliant systems, providing regulated 1.8 V / 3 V / 5 V card supply (VCC), integrated 26 MHz crystal oscillator, and three protected half-duplex I/O lines (C4/C7/C8) with thermal/short-circuit protection. It supports set-top box conditional access and banking card readers.

For engineers reviewing the ST8024LCDR datasheet, ST8024LCDR pinout, ST8024LCDR application, or ST8024LCDR equivalent, key selection criteria include VCC regulation accuracy (±5% at 5 V), step-up converter input range (4.75–6.5 V), clock division options (÷1/2/4/8), ESD robustness (>6 kV on card side), and PORADJ-adjustable power-on reset threshold.

Technical Context

The ST8024LCDR integrates a 26 MHz crystal oscillator and programmable clock divider (CLKDIV1/CLKDIV2) to generate synchronous card clocks up to 20 MHz. Its VCC generator uses an internal step-up converter powered by VDDP (4.75–6.5 V) to deliver tightly regulated 1.8 V (±6.5%), 3 V (±5%), or 5 V (±5%) to the smartcard contact C1.

It implements automatic activation/deactivation sequences triggered by hardware (e.g., short-circuit, card removal, VDD dropout) or software (CMDVCC/RSTIN), with built-in debounce on PRES inputs and NMOS open-drain OFF interrupt output. All card-side I/O lines feature enhanced ESD protection (>6 kV HBM) and slew-rate control.

Key Specifications

Pinout & Package

ST8024LCDR is housed in a 28-pin SOIC (SO-28) package with 0.6 mm pitch, 17.9 mm × 7.6 mm body, and tape-and-reel packaging (1000 units/reel). Pin functions are validated per STMicroelectronics Doc ID 17709 Rev 5, Table 2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ST8024LCDR, ST8024LCTR offers superior thermal dissipation in compact form, while ST8024LTR sacrifices clock flexibility and voltage options to reduce pin count and cost - selection depends on whether integrated oscillator, multi-voltage support, and SOIC assembly compatibility are required.

Availability

ST8024LCDR is available at Aetrix Electronics and suitable for smartcard readers for set-top boxes, IC card readers for banking, and identification systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ST8024LCDR 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, power management devices, and smartcard solutions for industrial, automotive, and consumer markets.

The ST8024L product line delivers fully integrated, standards-compliant smartcard interface ICs targeting secure transaction systems - emphasizing reliability, multi-voltage support, and embedded safety features for payment, identity, and conditional access applications.

FAQ

What is the maximum clock frequency the ST8024LCDR can deliver to the smartcard?

The ST8024LCDR generates a maximum card clock frequency of 20 MHz. This is achieved by dividing its internal 26 MHz oscillator by 1 (26 MHz ÷ 1 = 26 MHz), but the device limits CLK output to 20 MHz per ISO 7816-3 and EMV 4.2 specifications. Valid division ratios are ÷1, ÷2, ÷4, and ÷8, yielding 20 MHz, 10 MHz, 5 MHz, or 2.5 MHz outputs - all synchronized to avoid glitches during runtime changes.

Does the ST8024LCDR support 1.8 V smartcards, and how is it configured?

Yes, the ST8024LCDR supports 1.8 V smartcards via the 1.8V pin (pin 13 in SO-28), which overrides the 5V/3V pin when asserted high. When 1.8V = high, VCC is regulated to 1.8 V ±6.5% with ≤45 mA capability and ripple <350 mV (20 kHz–200 MHz). The 1.8V pin has an internal 11 kΩ pull-down resistor to GND, ensuring safe default behavior if left unconnected.

How does the ST8024LCDR handle card insertion and removal events?

The ST8024LCDR uses dual PRES inputs (active-low and active-high, bonding-selectable) with built-in hardware debounce to detect card presence. Upon insertion, it initiates automatic activation: enabling VCC, asserting RST, and starting CLK. On removal or short-circuit, it triggers emergency deactivation - disabling VCC within microseconds, releasing RST, and asserting OFF to notify the host MCU, all without firmware involvement.

Can the ST8024LCDR operate without an external crystal?

Yes. The ST8024LCDR integrates a 26 MHz crystal oscillator and requires no external crystal when used in SO-28 or TSSOP-28 packages (ST8024LCDR and ST8024LCTR). Pins XTAL1 and XTAL2 are internally connected to the oscillator circuit; XTAL2 must be left open if an external clock is applied to XTAL1. The TSSOP-20 variant (ST8024LTR) lacks this oscillator and requires an external clock source.