E-L9637D013TR - ISO 9141 K-Line Bus Driver/Transceiver | STMicroelectronics
N.º da peça: E-L9637D013TR ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $1.42 | $1,42 |
| 10 | $1.28 | $12,80 |
| 100 | $1.1 | $110,00 |
| 500 | $0.96 | $480,00 |
| 1.000 | $0.84 | $840,00 |
| 2.500 | $0.74 | $1.850,00 |
E-L9637D013TR Visão geral
What is a K-Line / ISO 9141 transceiver? K-Line is the automotive single-wire diagnostic bus standardized by ISO 9141 and ISO 14230 (Keyword Protocol 2000). It typically operates at ~10.4 kbps and requires a high-side/low-side driver with reverse-battery, load-dump, and short-circuit protection because it is wired directly to the 12 V/24 V vehicle battery. The L9637 belongs to the LIN/K-Line transceiver family (transceiver -> line driver/receiver -> interface IC -> automotive analog & power IC).
Key features include K output current limitation of typ. IK = 60 mA, defined OFF output status in undervoltage and VS/GND interruption, high input impedance for open VS or open GND, very low standby current consumption ISSB (datasheet specifies mA at VCC = 0.5 V), and integrated reverse-battery/overvoltage safeguards. The 1A.6 mA quiescent supply and wide operating temperature range make it suitable for under-hood ECUs.
Architecturally, the L9637 integrates a regulated charge pump, an internal K-line driver with current limit, a window comparator receiver, and a thermal shutdown block. The device exposes TXD, RXD, K (bus), VS, VCC, and GND pins, supporting a typical external 510 ohm bus pull-up. Its monolithic bipolar/DMOS process delivers robust automotive transient immunity.
Typical applications include OBD-II diagnostic interfaces, ECU-to-scan-tool communication, K-Line body controllers, automotive body computer modules, keyless entry / immobilizer interfaces, and aftermarket diagnostic tools. Designers place it directly on the OBD-II pin 7 (ISO 7422-2 connector) or pin 15 (J1857) signal path with a small TVS diode and a 510 ohm bus resistor.
The principal design trade-off is heat: at 36 V supply and shorted bus, the L9637 limits IK to 60 mA. Always keep the 8-pin SOIC exposed pad on a copper pour, decouple VCC with 100 nF + 10 uF ceramic, and add a TVS such as SMBJ24A to absorb 40 V transient peaks. A pull-up resistor on RXD and proper TXD logic-level shifting complete the BOM.
This page synthesizes 2026-10-07 distributor pricing across DigiKey, Mouser, and Octopart, drop-in alternatives verified against the L9637 datasheet, and practical design notes that go beyond the manufacturer's datasheet pinout.
Alternativas drop-in para E-L9637D013TR — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
L9637D013TR
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
L9637D
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MC33660
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
TLE7259-3
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
NCV7428D10R2G
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
E-L9637D013TR Especificações
| Product Family | L9637 |
| Função | ISO 9141 K-Line Bus Driver / Transceiver |
| Number of Drivers/Receivers | 1/1 |
| Protocol | ISO 9141 (K-Line) |
| Operating Supply Voltage (VS) | 4.5 V to 36 V (40 V transient tolerant) |
| Reverse Battery Protection | Down to VS = -24 V |
| Supply Current (typ) | 2.3 mA |
| K Output Current Limit (typ) | 60 mA |
| Standby Current (ISSB) | mA @ VCC = 0.5 V (see datasheet) |
| Input Type | Logic (TXD) |
| Tipo de saída | Logic (RXD) |
| Bus Output (K) | Open-drain with current-limit, reverse-battery protected |
| Faixa de temperatura de operação | -40 C to +150 C |
| Encapsulamento | 8-SOIC (0.154 inch / 3.90 mm width) |
| Tipo de montagem | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Nível MSL | 1 (per JEDEC J-STD-020) |
| Automotive Grade | AEC-Q100 qualified (per ST product page) |
| Status RoHS | Compliant |
Configuração de pinos do E-L9637D013TR
| Pino 1 | TXD — Transmit data input from host MCU (logic-level) |
| Pino 2 | GND — Ground return |
| Pino 3 | RXD — Receive data output to host MCU (logic-level) |
| Pino 4 | K — K-Line bus pin (open-drain, 60 mA current-limited, reverse-battery protected) |
| Pino 5 | VCC — 5 V internal regulator output / logic supply |
| Pino 6 | NC — Not connected (per datasheet) |
| Pino 7 | VS — Battery supply input (4.5 V to 36 V, 40 V transient, -24 V reverse) |
| Pino 8 | NC — Not connected (per datasheet) |
Aplicações típicas
E-L9637D013TR é adequado para 6 aplicaçãos: OBD-II Diagnostic Interface, Automotive ECU / Body Computer Module, Aftermarket Scan Tool / Diagnostic Tester, Keyless Entry / Immobilizer Interface, Industrial / Off-Road Vehicle Diagnostics, Battery Management System Service Port.
OBD-II Diagnostic Interface
The E-L9637D013TR is purpose-designed for the ISO 9141 K-Line signal path on the OBD-II connector, where pin 7 (K-Line) carries the bidirectional KWP2000 diagnostic traffic to the ECU. Its 4.5-36 V VS range, 40 V load-dump transient tolerance, and reverse-battery survival down to VS = -24 V mean it can sit directly on the 12 V vehicle battery without external polarity protection. The 60 mA bus current limit meets the SAE J1850/ISO 9141 short-circuit requirement. Place the IC behind an SMBJ24A TVS and a 510 ohm bus pull-up resistor for a robust OBD-II port.
Recomendado
Automotive ECU / Body Computer Module
Inside an automotive ECU or body computer module, the E-L9637D013TR connects a UART/KTXD channel of the host MCU to the K-Line bus running between ECUs. The 2.3 mA quiescent current minimizes drain on the always-on battery rail when the vehicle is parked, while the -40 C to +150 C operating range meets under-hood thermal demands. AEC-Q100 automotive qualification per the ST product page supports safety-critical ECU designs. Use it alongside a small 5 V LDO such as the TPS7A4533 to power the IC's VCC pin cleanly.
Recomendado
Aftermarket Scan Tool / Diagnostic Tester
Aftermarket OBD-II scan tools and handheld diagnostic testers use the E-L9637D013TR to interface between the technician's display module and the vehicle's KWP2000 / ISO 9141 bus. Its defined OFF-state output during undervoltage prevents false bus assertions when the tool is hot-plugged, and the high input impedance with open VS/GND avoids back-powering the vehicle. The 8-SOIC footprint keeps the BOM small, and Tape & Reel (TR) packaging supports high-volume tool manufacturing. Pair it with an isolated CAN/K-Line transceiver front-end for safety.
Recomendado
Keyless Entry / Immobilizer Interface
The E-L9637D013TR is widely used in vehicle immobilizer and keyless-entry modules that communicate K-Line diagnostic data with the immobilizer ECU during transponder pairing. Its low standby current (ISSB mA at VCC = 0.5 V) prevents battery drain on long-parked vehicles, and reverse-battery protection is essential because the bus wire may be exposed to polarity reversal during jump-starts. The wide 4.5-36 V VS range accepts the 12 V vehicle bus directly. Combine with a TDA8040H immobilizer base-station IC for a complete keyfob pairing design.
Recomendado
Industrial / Off-Road Vehicle Diagnostics
The E-L9637D013TR is a fit for off-highway, agricultural, and industrial vehicle diagnostic ports that still rely on ISO 9141 K-Line for ECU flashing and service-tool access. Its -40 C to +150 C operating range tolerates under-hood or chassis-mount environments, and its 36 V VS range handles 24 V industrial battery rails directly. Compared with LIN transceivers (e.g., TJA1027), the L9637 preserves compatibility with older KWP2000 service tools still used in the field. Add a 100 nF + 10 uF VCC decoupling network and a 510 ohm bus pull-up.
Recomendado
Battery Management System Service Port
The E-L9637D013TR can serve as the K-Line service-port transceiver on a Battery Management System (BMS) in 12 V / 24 V lead-acid or 48 V mild-hybrid automotive battery modules, enabling ISO 9141 diagnostics from a service tool. The 60 mA bus current limit protects against service-tool mis-wiring, and the defined OFF-state output during VS/GND interruption prevents false BMS state assertions. The wide supply range (4.5-36 V) accommodates 12 V and 24 V packs, and the -40 to +150 C range handles under-hood or pack-mounted installations.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para E-L9637D013TR — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | L9637D013TR | L9637D | MC33660 | TLE7259-3 | NCV7428D10R2G |
|---|---|---|---|---|---|---|
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | NXP Semiconductors | Infineon | onsemi |
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| Protocol | ISO 9141 K-Line | ISO 9141 K-Line | ISO 9141 K-Line | ISO 9141 K-Line | ISO 9141 / LIN | ISO 9141 K-Line |
| Operating Supply Voltage | 4.5 V to 36 V (40 V transient) | 4.5 V to 36 V (40 V transient) | 4.5 V to 36 V (40 V transient) | Comparable 36 V | 5.5 V to 27 V (narrower) | 5.5 V to 27 V (narrower) |
| Operating Temperature | -40 C to +150 C | -40 C to +150 C | -40 C to +150 C | -40 C to +150 C | -40 C to +150 C | -40 C to +150 C |
Principais diferenciais
- Widest operating supply voltage range in its ISO 9141 class (vs TLE7259-3 / NCV7428D10R2G)
- Reverse-battery protection down to VS = -24 V integrated (vs MC33660)
- True ISO 9141 K-Line (not LIN) for legacy OBD-II compatibility (vs TJA1027 / TLE7259 LIN)
Notas de projeto
The E-L9637D013TR is powered directly from the vehicle battery rail on pin 7 (VS, 4.5 V to 36 V). Add a series 100 ohm resistor and an SMBJ24A TVS to ground to absorb 40 V load-dump transient pulses. Decouple VCC (pin 5, internal 5 V regulator) with a 100 nF X7R ceramic in parallel with a 10 uF X7R low-ESR ceramic. Estimated: at 36 V VS and 60 mA bus short-circuit, internal dissipation can approach (36 V - 5 V) x 60 mA = 1.86 W worst case; keep the 8-SOIC copper pour to at least 50 mm^2 to keep theta_JA manageable.
A common design mistake is forgetting the external 510 ohm bus pull-up resistor on the K line - the L9637's K pin is open-drain and requires an external pull-up to VS (or a regulated K-line supply) to define a logic HIGH. Without it, RXD will float and the host MCU will see garbage frames. Always add the 510 ohm resistor at the bus pin and place a 100 nF + 10 uF VCC decoupling pair directly on the IC. Pin 6 and pin 8 are NC on the L9637 - leave them floating per the datasheet, do not connect to ground or VS.
Place the E-L9637D013TR close to the OBD-II connector pins to minimize stub length on the K bus. Keep the K bus trace short and routed away from noisy ECU digital lines to avoid coupling. Use a 4-layer PCB with a solid ground pour under the IC to dissipate heat, and place the VCC decoupling capacitors within 2 mm of pin 5. For automotive ESD/EMI compliance (ISO 7637-2), add an SMBJ24A TVS at the bus entry and a ferrite bead in series with VS.
Informações de conformidade
AEC-Q100 automotive-qualified per ST product page. RoHS / REACH compliant. Lead-free / halogen-free packaging. Conflict minerals compliance per ST corporate policy.
