May 30, 2012
Analog and mixed signal leading supplier – AiT Semiconductor Inc. provide the
perfect products to CAR DVD Power Solution.
The A7210 is a CMOS‐based PWM step‐down DC‐DC Controller. The A7210 offers the
lower supply current and wider operating input‐voltage range. The A7210 consists of
an oscillator, a PWM control circuit, a reference voltage unit, an error amplifier, a
soft‐start circuit, a protection circuit, a PWM/PFM alternative circuit, a Chip Enable
circuit, and under voltage lockout circuit.
A low ripple, high efficiency step‐down DC‐DC converter can be easily composed of
A7210. Output Voltage can be adjusted with external resistors.
The A7210 uses voltage type PWM/PFM mixed operation mode. When the load
current is small, the operation will switch into the PFM mode from PWM mode.
Therefore the efficiency at small load is improved, and then the chip works on PWM
The A7210 embeds reset type protection circuit. If the term of maximum duty cycle
keeps on a certain time, the protection circuit restarts the operation with soft‐start
and repeat this operation until maximum duty cycle condition is released. When the
cause of large load current is removed, the chip returns to normal condition. The
A7210 is available in tiny SOT‐25 Package for PCB space saving.
The A7220 is a current mode synchronous buck converter, and has a proprietary
circuit that enables fast transient response, enables the device to adopt to both low
ESR output capacitors, such as POSCAP or SP‐CAP, and ultra‐low ESR ceramic
The A7220 operates from 4.3V to 18V input, and the output voltage can be
programmed between 0.918V to 14V with 2A output current.
Due to 95mΩ (High side) and 90mΩ (Low side) integrated FETs, the A7220 works in
high efficiency (up to 94% @12V Input, 3.3V output).
The A7220 is available in SOP8 Package to stand higher power consumption.