Microchip Technology AT83C24NDS-PRTUL

Overview

AT83C24NDS-PRTUL from Microchip Technology is a smart card interface IC with integrated DC/DC converter, designed for NDS VideoGuard conditional access systems in set-top boxes. It delivers programmable 1.8V/3V/5V card supply (±0.14V at 1.8V, ±0.2V at 3V, ±5% at 5V), supports ISO 7816/EMV2000/GSM standards, and features 8 kV+ ESD protection on card interface pins. Its 18–48 MHz clock input and industrial temperature range (−40°C to +85°C) enable robust operation in broadcast security applications.

For engineers reviewing the AT83C24NDS-PRTUL datasheet, AT83C24NDS-PRTUL pinout, AT83C24NDS-PRTUL application, or AT83C24NDS-PRTUL equivalent, this page provides verified technical context, validated pin functions, confirmed operating modes (hardware/software activation, transparent mode), real-world power-down current (30 µA typical), and precise NDS-specific constraints including mandatory 3.3 µF CVCC decoupling and 18 MHz minimum clock.

Technical Context

The AT83C24NDS-PRTUL implements a dual-path clock controller supporting CCLK generation from CLK, A2/CK, DCCLK, or CARDCK - with hardware activation requiring CLK ≥18 MHz per NDS specification. Its TWI interface enables up to 8 devices on one bus via programmable A2/A1/A0 address selection (0x40–0x4E write addresses), and supports both software-configured activation (via CONFIG0–CONFIG4 registers) and hardware-triggered activation via CMDVCC pin.

It integrates a high-efficiency step-up converter (80–98% efficiency), voltage supervisor with POR/PFD, and automatic reset transition (ART) logic that times CRST assertion relative to card clock cycles (tb ≥400 cycles, tc ≤40000 cycles per ISO 7816). Card presence detection uses CPRES with configurable polarity and filtering (CDS[2:0]), while I/O level shifting bridges EVCC (1.6V–VCC) and CVCC domains.

Key Specifications

Pinout & Package

AT83C24NDS-PRTUL is available in SO28 and QFN28 packages. Both packages share identical pin functions and electrical characteristics per Microchip documentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT83C24B-PRTUL, AT83C24NDS-PRTUL enforces stricter clock (18 MHz min) and CVCC (3.3 µF) requirements for NDS certification, while SLB9670TT20 serves a fundamentally different security architecture - making AT83C24NDS-PRTUL the sole fit for VideoGuard-integrated STBs.

Availability

AT83C24NDS-PRTUL is available at Aetrix Electronics and suitable for set-top box conditional access, EMV payment terminal design, secure ID reader development, and GSM SIM interface modules requiring stable component supply across long-lifecycle consumer electronics programs.

Supply support for AT83C24NDS-PRTUL 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

Microchip Technology is a global semiconductor company specializing in microcontrollers, analog devices, and security ICs, with leadership in embedded control and trusted computing solutions.

The AT83C24 product line was designed specifically for smart card reader/writer applications in EFT/POS, set-top boxes, and secure identification systems - emphasizing low power, high integration, and standards compliance (ISO 7816, EMV2000, GSM).

FAQ

What distinguishes AT83C24NDS-PRTUL from the standard AT83C24B?

The AT83C24NDS-PRTUL is a NDS-certified variant of the AT83C24B with three key differences: (1) mandatory 18 MHz minimum input clock for ART timing compliance, (2) tighter CVCC voltage tolerance (4.75–5.25V vs. 4.6–5.25V), and (3) requirement for exactly 3.3 µF decoupling on the CVCC pin - whereas AT83C24B allows up to 10 µF. These constraints ensure interoperability with NDS VideoGuard conditional access software in set-top boxes.

Does AT83C24NDS-PRTUL support 1.8V smart cards?

Yes, AT83C24NDS-PRTUL supports 1.8V smart cards with ±0.14V regulation at up to 40 mA. This is configured via VCARD[1:0] bits in the CONFIG0 register. The device automatically adjusts CVCC output and enables appropriate level-shifting on CIO/CC4/CC8 to maintain signal integrity at the lower voltage, meeting ISO 7816 Class C requirements.

What is the purpose of the CMDVCC pin on AT83C24NDS-PRTUL?

The CMDVCC pin on AT83C24NDS-PRTUL serves as a hardware activation trigger: a falling edge initiates the full smart card power-up sequence - including DC/DC startup, CVCC ramp, CCLK enable, and CRST synchronization - without host CPU intervention. This simplifies firmware design in resource-constrained STB platforms and ensures deterministic timing for NDS VideoGuard handshaking.

Can AT83C24NDS-PRTUL operate without the integrated DC/DC converter?

Yes, AT83C24NDS-PRTUL can bypass the step-up converter by tying LI directly to VCC and setting the STEPREG bit in CONFIG4 to '1'. In this regulator mode, CVCC is derived directly from VCC (within 3V–5.5V range), eliminating external inductor requirements. However, this disables programmable 5V CVCC generation - limiting operation to cards compatible with the host's supply voltage.

How does AT83C24NDS-PRTUL handle card insertion and removal detection?

AT83C24NDS-PRTUL uses the dedicated CPRES pin for card presence detection, with polarity configurable via the CARDDET bit and noise filtering adjustable via CDS[2:0] bits in CONFIG1. An interrupt is generated on PRES/INT (when IT_SEL=0) or level-changed (when IT_SEL=1, NDS-mandatory) upon insertion/removal. The internal pull-up on CPRES can be disabled to reduce quiescent current, requiring an external resistor network.