Analog Devices Inc./Maxim Integrated MAX1740EUB+

Overview

The MAX1740EUB+ from Maxim Integrated is a SIM/smart card level translator IC that provides bidirectional data, unidirectional clock and reset level shifting between controller-side (DVCC = +1.425V to +5.5V) and card-side (VCC = +2.25V to +5.5V) domains, with ±10kV HBM ESD protection on all card-contact pins, 2.5µA max operating supply current, and SHDN-controlled shutdown for safe SIM insertion/removal in GSM handsets.

For engineers reviewing the MAX1740EUB+ datasheet, MAX1740EUB+ pinout, MAX1740EUB+ application, or MAX1740EUB+ equivalent, key selection considerations include its dual-voltage domain support (DVCC ≤ VCC or DVCC ≥ VCC), active low shutdown behavior (CLK/RST/IO pulled low), integrated 20kΩ DATA pull-up to DVCC, 10-pin µMAX package footprint, and compliance with GSM 11.11/11.12 test specifications.

Technical Context

The MAX1740EUB+ implements three dedicated level-shifting paths: CIN→CLK and RIN→RST use unidirectional transfer gates, while DATA↔IO uses a bidirectional transfer gate with internal pull-ups (20kΩ to DVCC on DATA, 10kΩ to VCC on IO). It requires no external logic or biasing and supports voltage translation regardless of relative DVCC/VCC magnitude.

Shutdown is triggered by driving SHDN low (MAX1740-specific), disabling the DATA–IO transfer gate and actively pulling CLK, RST, and IO to GND via internal switches; total supply current drops to 0.01µA. ESD protection is implemented per Human Body Model on CLK, RST, IO, VCC, and GND pins - verified to ±10kV in all operational and power-down states.

Key Specifications

Pinout & Package

The MAX1740EUB+ is housed in a 10-pin µMAX package (3mm × 3mm, 1.09mm height), RoHS-compliant, with no exposed pad. Pin pitch is 0.5mm; lead finish is matte tin.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SIM/smart card level translation applications.

Compared with MAX1741EUB+, the MAX1740EUB+ provides SHDN-based safe insertion control but cannot drive push-pull DATA lines; compared with TXS0102DCUR, it delivers certified ±10kV ESD protection and GSM compliance at the cost of fixed function and higher integration.

Availability

MAX1740EUB+ is available at Aetrix Electronics and suitable for GSM handset design, smart card reader manufacturing, and SPI/MICROWIRE level translation requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.

Supply support for MAX1740EUB+ 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, communications, computing, and consumer applications.

The MAX1740EUB+ belongs to Maxim's SIM/smart card interface product line, engineered specifically to simplify certified, low-power, ESD-robust SIM connectivity in space-constrained portable electronics.

FAQ

What is the primary function of the MAX1740EUB+ in a GSM handset design?

The MAX1740EUB+ serves as a dedicated SIM/smart card level translator, providing voltage-domain isolation and bidirectional data translation between a low-voltage controller (e.g., 1.8V baseband SoC) and a 3V or 5V SIM card. It integrates ±10kV ESD protection on all card-contact pins and supports safe hot-insertion via its SHDN pin, which actively pulls CLK, RST, and IO low during card swap. This eliminates discrete level shifters and ESD components in the MAX1740EUB+ signal path.

Does the MAX1740EUB+ require external pull-up resistors on the DATA or IO lines?

No, the MAX1740EUB+ includes internal pull-up resistors: 20kΩ from DATA to DVCC and 10kΩ from IO to VCC. These eliminate the need for external pull-ups in standard open-drain configurations. The internal pull-ups ensure valid logic-high levels during idle states and maintain compatibility with ISO/IEC 7816-3 timing requirements. External pull-ups are unnecessary unless custom current or rise-time constraints demand tighter values.

Can the MAX1740EUB+ operate with DVCC lower than VCC, such as 1.8V controller to 3V SIM card?

Yes, the MAX1740EUB+ explicitly supports DVCC ≤ VCC operation - including 1.8V DVCC with 3V VCC - as confirmed in its "Features" list ("Allows Level Translation with DVCC ≥ VCC or DVCC ≤ VCC"). Its transfer-gate architecture ensures correct logic level translation in both directions without configuration changes, making it suitable for modern low-voltage processors interfacing with legacy 3V/5V smart cards.

What happens to the CLK, RST, and IO pins when SHDN is driven low on the MAX1740EUB+?

When SHDN is driven low, the MAX1740EUB+ enters shutdown mode: CLK, RST, and IO are actively pulled low via internal NMOS switches; the DATA–IO bidirectional transfer gate is disabled; and total supply current drops to 0.01µA. This guarantees all card-contact pins are at GND before physical insertion or removal, satisfying GSM 11.11/11.12 mechanical safety requirements. The behavior is deterministic and does not rely on external pull-downs.

Is the MAX1740EUB+ compliant with any industry-standard test specifications?

Yes, the MAX1740EUB+ is explicitly compliant with GSM test specifications 11.11 and 11.12, which define electrical, timing, and ESD requirements for SIM card interfaces in cellular handsets. Its ±10kV HBM ESD rating on CLK, RST, IO, VCC, and GND pins was validated per these standards, enabling direct use in certified GSM designs without additional system-level ESD hardening.