STMicroelectronics ST8024LCTR

Overview

ST8024LCTR from STMicroelectronics is a smartcard interface IC compliant with ISO 7816, GSM11.11, and EMV 4.2 standards, supporting 1.8 V, 3 V, and 5 V card supply voltages (VCC), integrated 26 MHz crystal oscillator, and three protected half-duplex I/O lines (C4, C7, C8) for secure contact-based smartcard communication in set-top box readers.

For engineers reviewing the ST8024LCTR datasheet, ST8024LCTR pinout, ST8024LCTR application, or ST8024LCTR equivalent, key selection considerations include VCC regulation accuracy (±5% at 5 V), thermal/short-circuit protection on all card contacts, programmable clock division (÷1/2/4/8), hardware- and software-initiated activation/deactivation sequences, and TSSOP-28 package compatibility with NDS conditional access systems.

Technical Context

The ST8024LCTR implements a fully integrated analog smartcard interface with independent step-up converter (VDDP-powered) generating regulated VCC at 1.8 V ±6.5%, 3 V, or 5 V ±5%, featuring filtered overload detection (~120 mA), controlled slew rates (0.08–0.22 V/µs), and automatic fault response including thermal shutdown and short-circuit deactivation.

It integrates a 26 MHz crystal oscillator (XTAL1/XTAL2), synchronous clock generation up to 20 MHz with CLKDIV1/CLKDIV2 control, non-inverted RSTIN-driven reset logic, and multiplexed OFF status signal, while supporting dual power domains (VDD for logic, VDDP for VCC generation) and ESD protection >6 kV on card-side pins.

Key Specifications

Pinout & Package

TSSOP-28 package (8.6 mm × 3.9 mm, 0.65 mm pitch), lead-free, RoHS-compliant, rated for –25 °C to +85 °C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ST8024LCDR, ST8024LCTR offers identical functionality in a smaller TSSOP-28 package with better thermal resistance (50 °C/W vs. 56 °C/W), while ST8024LTR sacrifices clock programmability and dual auxiliary channels to achieve lower pin count and cost - making ST8024LCTR optimal for space-constrained, multi-voltage, EMV-certified designs.

Availability

ST8024LCTR is available at Aetrix Electronics and suitable for smartcard readers in set-top boxes, banking terminals, pay-TV conditional access modules, and secure identification systems requiring stable component supply across extended industrial temperature ranges.

Supply support for ST8024LCTR 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, MEMS, and smart power devices for industrial, automotive, and consumer markets.

The ST8024L series belongs to ST's secure interface product line, engineered specifically for ISO 7816-compliant smartcard applications in pay-TV, financial transaction, and government ID systems - emphasizing robustness, certification readiness, and minimal external component count.

FAQ

What is the maximum allowable current draw on the VCC pin, and how does overload protection respond?

The ST8024LCTR supports up to 80 mA at 5 V, 65 mA at 3 V, and 45 mA at 1.8 V on the VCC pin. Overload detection triggers at ~120 mA with filtered response; beyond this, the device initiates automatic deactivation - disabling VCC, CLK, and RST - and asserts the OFF pin to signal fault condition to the MCU. Recovery requires CMDVCC reassertion or software reset.

Can the ST8024LCTR generate a 13.56 MHz clock for contactless coexistence, or is it limited to contact smartcards?

The ST8024LCTR is designed exclusively for contact smartcards per ISO 7816, with clock generation limited to synchronous outputs up to 20 MHz derived from its 26 MHz internal oscillator (divided by 1, 2, 4, or 8). It does not support 13.56 MHz RF carrier generation or contactless protocols like ISO 14443; that function requires separate NFC/RFID controllers such as ST's ST25R series.

How does the PORADJ pin affect power-on reset behavior, and what resistor values are recommended?

PORADJ sets the external power-on reset threshold via a resistor divider from VDD to GND. With no external divider, internal threshold is 2.45 V ±100 mV. For custom thresholds, use R1 (VDD to PORADJ) and R2 (PORADJ to GND) such that VTH = VDD × R2/(R1+R2); typical values are R1 = 100 kΩ, R2 = 47 kΩ for ~3.3 V reset. Threshold hysteresis is 30–90 mV depending on divider impedance.

Is the ST8024LCTR compatible with both Class A (5 V) and Class C (1.8 V) smartcards in the same design without hardware changes?

Yes - the ST8024LCTR supports automatic Class A/B/C card voltage selection via the 5V/3V and 1.8V pins. Driving 1.8V high forces 1.8 V VCC regardless of 5V/3V state; otherwise, 5V/3V alone selects 5 V or 3 V. No external components or solder bridges are required to support all three classes, enabling single-hardware designs for global deployment.