Overview
The L9637D is a monolithic integrated circuit designed by STMicroelectronics, specifically tailored to provide ISO 9141 compatible interface functions. This device is optimized for bidirectional serial communication in automotive diagnostic systems. It features a robust design with various protections and low power consumption, making it highly efficient for automotive bus systems.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Supply Voltage (VS) | 4.5 | - | 36 (40 V for transients) | V |
| Stabilized Voltage (VCC) | -0.3 | - | 7 | V |
| Pin Voltage (VLI, K) | -24 | - | VS | V |
| Pin Voltage (VLO, RX, TX) | -24 | - | VCC | V |
| Junction Temperature (Tj) | -40 | - | 150 | °C |
| Supply Current (ICC) @ VCC ≤ 5.5V | - | 1.4 | 2.3 | mA |
| Standby Current (ISSB) @ VCC ≤ 0.5V | - | <1 | - | mA |
| K Output Current Limitation | - | 60 | - | mA |
| Temperature Shutdown Switch-On Threshold | 160 | - | 200 | °C |
Key Features
- Operating power supply voltage range: 4.5 V to 36 V (40 V for transients)
- Reverse supply (battery) protection down to -24 V
- Standby mode with very low current consumption (ISSB ≤ 1 mA @ VCC ≤ 0.5 V)
- Low quiescent current in off condition (ISOFF = 120 µA)
- TTL compatible TX input
- Bidirectional K-I/O pin with supply voltage dependent input threshold
- Wide input and output voltage range: -24 V ≤ VK ≤ VS
- K output current limitation: typ. IK = 60 mA
- Defined OFF output status in undervoltage condition and VS or GND interruption
- Controlled output slope for low EMI
- High input impedance for open VS or GND connection
- Defined output ON status of LO or RX for open LI or K inputs
- Defined K output OFF for TX input open
- Integrated pull up resistors for TX, RX, and LO
- Overtemperature shut down function selective to K-I/O pin
- EMI robustness optimized
Applications
The L9637D is primarily used in automotive diagnostic systems, providing a bidirectional serial communication link according to the ISO 9141 specification. It is suitable for various automotive applications where reliable and efficient communication between electronic control units (ECUs) and diagnostic tools is required.
Q & A
- What is the primary function of the L9637D?
The L9637D is a monolithic integrated circuit designed to provide ISO 9141 compatible interface functions for bidirectional serial communication in automotive diagnostic systems. - What is the operating power supply voltage range of the L9637D?
The operating power supply voltage range is from 4.5 V to 36 V, with transient protection up to 40 V. - Does the L9637D have reverse battery protection?
Yes, the L9637D has reverse supply (battery) protection down to -24 V. - What is the standby current consumption of the L9637D?
The standby current consumption (ISSB) is less than 1 mA when VCC is less than or equal to 0.5 V. - Is the L9637D TTL compatible?
Yes, the TX input of the L9637D is TTL compatible. - What is the K output current limitation of the L9637D?
The K output current limitation is typically 60 mA. - How does the L9637D handle overtemperature conditions?
The L9637D has an overtemperature shut down function selective to the K-I/O pin, with a switch-on threshold between 160°C and 200°C. - Is the L9637D EMI robust?
Yes, the L9637D is optimized for EMI robustness. - What kind of resistors are integrated into the L9637D?
The L9637D has integrated pull-up resistors for TX, RX, and LO. - What is the typical quiescent current in the off condition?
The typical quiescent current in the off condition (ISOFF) is 120 µA. - What are the package options for the L9637D?
The L9637D is available in SO-8 packages, including tube and tape and reel options.
