STMicroelectronics ST8024LACTR

Overview

ST8024LACTR from STMicroelectronics is a smartcard interface IC designed for ISO 7816, EMV 4.2, and GSM11.11-compliant systems. It provides regulated 1.8 V ±6.5% card supply (VCC), integrated 26 MHz crystal oscillator, three protected half-duplex I/O lines (C4/C7/C8), thermal/short-circuit protection, and automatic activation/deactivation sequences. It serves as the analog front-end between microcontrollers and Class A/B/C smartcards in pay-TV conditional access systems.

For engineers reviewing the ST8024LACTR datasheet, ST8024LACTR pinout, ST8024LACTR application, or ST8024LACTR equivalent, key selection considerations include VCC regulation accuracy (±6.5% at 1.8 V), step-up converter operation with 4.75–6.5 V VDDP input, 26 MHz internal oscillator, ESD protection (>6 kV on card side), and TSSOP-28 package compatibility with NDS-certified set-top box designs.

Technical Context

The ST8024LACTR implements a fully integrated smartcard power and signal interface with dual-supply architecture: VDD (2.7–6.5 V) powers logic and MCU-side interfaces, while VDDP (4.0–6.5 V) feeds a dedicated step-up converter generating precise VCC outputs (1.8 V, 3 V, or 5 V). Its clock circuitry supports synchronous frequency division (÷1/÷2/÷4/÷8) up to 20 MHz card clock output with glitch-free transitions.

It features hardware-controlled activation via CMDVCC and RSTIN, built-in debounce on card presence inputs (PRES/PRES), non-inverted RST control, and an NMOS open-drain OFF interrupt output with 20 kΩ internal pull-up to VDD. All card-contact pins (I/O, RST, AUX1, AUX2, CLK) include thermal and short-circuit protection plus >6 kV HBM ESD rating.

Key Specifications

Pinout & Package

TSSOP-28 package: 0.65 mm lead pitch, 4.4 mm × 9.7 mm body size, exposed pad not present, moisture sensitivity level MSL3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ST8024LTR and ST8024LCTR, the ST8024LACTR uniquely combines TSSOP-28 packaging, 1.8 V VCC support, and full clock division capability-making it the only variant qualified for NDS-compliant 1.8 V smartcard systems requiring flexible timing control.

Availability

ST8024LACTR is available at Aetrix Electronics and suitable for pay TV set-top boxes, EMV banking terminals, government ID readers, and secure access control systems requiring stable component supply across long product lifecycles.

Supply support for ST8024LACTR 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 series was developed specifically for ISO 7816-compliant smartcard readers in broadcast conditional access and financial transaction systems, emphasizing integration, fault resilience, and multi-voltage interoperability.

FAQ

What is the maximum card supply current supported by ST8024LACTR at 1.8 V?

The ST8024LACTR delivers up to 45 mA continuous current at 1.8 V VCC output, with short-circuit protection activating at approximately 120 mA. This meets ISO 7816 Class C requirements and supports modern low-power smartcards used in pay-TV and eID applications.

Can ST8024LACTR generate a 10 MHz card clock with synchronous frequency change?

Yes. Using CLKDIV1 and CLKDIV2 pins, ST8024LACTR divides its 26 MHz internal oscillator to produce 20 MHz, 10 MHz, 5 MHz, or 2.5 MHz card clocks. Frequency changes are synchronous and glitch-free, satisfying EMV and ISO 7816 timing constraints for hot clock reconfiguration.

How does the step-up converter in ST8024LACTR differ from standard charge-pump regulators?

The ST8024LACTR's step-up converter uses a dedicated VDDP input (4.0–6.5 V) and PGND reference to generate VUP, which feeds a precision linear VCC regulator. Unlike basic charge pumps, it includes filtered overload detection (~120 mA), slew-rate control, and ripple suppression (<350 mV_P-P) optimized for smartcard power integrity.

Is external crystal loading required when using the internal 26 MHz oscillator?

No. The 26 MHz oscillator is fully integrated with internal capacitors; no external crystal or load capacitors are needed. Pins XTAL1 and XTAL2 are reserved for optional external clock injection-XTAL2 must be left open if internal oscillator is used, per datasheet Figure 2 and Table 9.