Torex Semiconductor launched the XD9704/XD9705 new series of step-down DC/DC converters
Torex Semiconductor has introduced the XD9704/XD9705 series, a family of 36 V high-voltage, 600 mA synchronous step-down DC/DC converters designed for automotive applications.
The devices are designed to meet AEC-Q100 Grade 1 requirements, with an operating temperature range of −40°C to +125°C. The series targets automotive power rails where designers need a combination of high input-voltage tolerance, compact implementation, low power consumption, high efficiency, and reliable operation during automotive voltage transients.
The converters support an input voltage of up to 36 V, with tolerance for a 46 V peak voltage for up to 400 ms. This makes them suitable for automotive systems connected to vehicle +B power inputs, where voltage disturbances can occur.
A key architectural feature is the use of an integrated P-channel driver FET rather than the N-channel driver FET commonly used in many medium/high-voltage DC/DC converters. According to Torex, this enables 100% duty-cycle operation, allowing the output to follow the input when the input voltage temporarily falls below the programmed output voltage - for example, during vehicle cranking.
The series is particularly positioned as a compact, efficient alternative to larger high-/medium-voltage LDO regulators, helping reduce heat generation and PCB area in automotive electronic systems. Torex specifically highlights sensor and communication-related automotive equipment and other applications requiring high reliability and small form factors.
Specifications
| Parameter | Value |
| Input voltage | 36V rated, 46V peak (≤400ms) |
| Output current | Up to 600mA |
| Switching frequency | 2.2MHz |
| Mounting area | As small as 48.7mm² |
| Quiescent current | 11μA |
| Peak efficiency | Up to 90% at VIN=12V, VOUT=5V, IOUT=1mA |
| Operating temperature | -40°C to +125°C |
| Package | SOT-89-5 (available now); DFN1820-6J (compact, under development) |
| Compliance | AEC-Q100 Grade 1 |
Key Features
- P-channel driver FET architecture - unlike conventional DC/DC converters that use an N-channel driver FET, this series integrates a P-channel driver FET, enabling 100% duty-cycle operation.
- Cold-crank support - during engine cranking or other low-input-voltage conditions, the converter can pass the input voltage directly to the output, maintaining reliable operation even with a small input-to-output voltage differential.
- Power sequencing aids - the devices include Power Good and soft-start functions to simplify power sequencing.
- Small solution size - the 2.2MHz switching frequency allows the use of small inductors and capacitors, shrinking total mounting area to just 48.7mm².
- High light-to-heavy-load efficiency - the low 11μA quiescent current supports up to 90% efficiency across a wide load range.
- Two control-mode variants:
- XD9704 series uses fixed F-PWM control for low-ripple operation.
- XD9705 series uses automatic PWM/PFM mode switching for maximum efficiency across a wide load range.
Applications
Although the XD9704/XD9705 are automotive-qualified products, Torex also identifies industrial equipment as a target area for the compact high-voltage architecture.
Potential applications include:
- Industrial sensors
- Monitoring systems
- Communication equipment
- Factory automation electronics
- Compact control modules
- High-voltage input embedded electronics
The combination of 36 V input capability, 600 mA output, compact packaging and high efficiency makes the architecture useful wherever PCB space and thermal performance are important.
