16V 40A fixed-frequency dc-dc converter has fast transient response
- 著者:Ella Cai
- 公開：:2017-09-19
Texas Instruments has introduced a 16V input, 40A synchronous DC/DC buck converter with internally compensated ‘advanced-current-mode’ (ACM) control supporting frequency synchronisation.
Called TPS543C20, its low resistance high and low-side mosfets contribute to over 90% efficiency from a 40pin, 5 x 7mm 1.5mm high QFN package – which sinks heat through a ground pad.
Two of the converters can operate side-by-side to drive loads up to 80A “for processors in space-constrained and power-dense applications in various markets, including wired and wireless communications, enterprise and cloud computing, and data storage systems”, said the firm.
Why advanced current mode?
“It is similar to emulated peak-current-mode control, which maintains stability over a range of input and output voltages for fast transient response,” said TI. “What makes ACM different is that it is a ramp based, peak current mode control scheme that internally generates a ramp to achieve true fixed frequency, without using external compensation. This provides the best of both traditional fixed frequency for low noise operation and constant on-time (COT) control for fast transient without external compensation. As well, ACM has good immunity for power-stage (inductor and capacitor) variation.” voltages.”
There is more on TI’s ACM here. and a comparison of the firm’s control strategies here.
Reference voltage accuracy in the TPS543C20 is 0.5% over temperature, and full differential remote-voltage sensing is provided.
TI 1V 20A buck reference designA reference design has been developed – for a 1V 20A synchronous buck converter (right), and the firm’s Webench on-line toos are available for design.
For similar applications at 25 A, TI offers the pin-compatible TPS543B20 and “For applications requiring PMBus , TI offers the 35A TPS546C23,” it said.
Called TPS543C20, its low resistance high and low-side mosfets contribute to over 90% efficiency from a 40pin, 5 x 7mm 1.5mm high QFN package – which sinks heat through a ground pad.
Two of the converters can operate side-by-side to drive loads up to 80A “for processors in space-constrained and power-dense applications in various markets, including wired and wireless communications, enterprise and cloud computing, and data storage systems”, said the firm.
Why advanced current mode?
“It is similar to emulated peak-current-mode control, which maintains stability over a range of input and output voltages for fast transient response,” said TI. “What makes ACM different is that it is a ramp based, peak current mode control scheme that internally generates a ramp to achieve true fixed frequency, without using external compensation. This provides the best of both traditional fixed frequency for low noise operation and constant on-time (COT) control for fast transient without external compensation. As well, ACM has good immunity for power-stage (inductor and capacitor) variation.” voltages.”
There is more on TI’s ACM here. and a comparison of the firm’s control strategies here.
Reference voltage accuracy in the TPS543C20 is 0.5% over temperature, and full differential remote-voltage sensing is provided.
TI 1V 20A buck reference designA reference design has been developed – for a 1V 20A synchronous buck converter (right), and the firm’s Webench on-line toos are available for design.
For similar applications at 25 A, TI offers the pin-compatible TPS543B20 and “For applications requiring PMBus , TI offers the 35A TPS546C23,” it said.
