Max5098a launched by Maxim company is a dual output, high switching frequency DC-DC converter with integrated high side or low side n-channel switch. Each output can be configured as a buck converter or a boost converter. When configured as a buck converter, the output currents of converter 1 and converter 2 are 2a and 1A respectively. Max5098a also integrates load shedding protection circuit, which can withstand transient voltage up to 80V in automotive applications. The load shedding protection circuit uses an internal charge pump to drive the gate of an external n-channel MOSFET. In case of overvoltage or load shedding, the series protection MOSFET can absorb high-voltage transients to prevent damage to low-voltage devices.

The working voltage range of DC-DC converter is wide: 4.5V to 19v. Max5098a operates in 180 ° phase staggering mode and the switching frequency is adjustable. This feature enables designers to find a balance between size, efficiency and cost while greatly reducing the number of external components. The high switching frequency (up to 2.2MHz) also allows the device to work outside the AM band, which is very suitable for automotive applications.

The device adopts voltage mode control to realize stable operation and external compensation, so the loop gain can be adjusted to optimize device selection and transient response. The device can be synchronized with the external clock at the sync input. At the same time, the clock output (CKO) allows the two devices to adopt the master-slave connection mode and four phase synchronous switching frequency. Other features include internal digital soft start, independent enabling of each DC-DC regulator (En1 and en2), open drain power ready output (pgood1 and pgood2) and shutdown input (on / off).

Other features of max5098a include overvoltage protection, short circuit (burping current limit) and thermal protection. Max5098a provides 5mmx5mm, 32 pin TQFN package with good heat dissipation and bare pad, and operates in the temperature range of – 40 ℃ to + 125 ℃.

Performance characteristics and application of high switching frequency DC-DC converter max5098a

Max5098a product features

4.5V to 5.5V or 5.2v to 19v input voltage range (up to 80V load shedding protection);

Dual output DC-DC converter integrated power MOSFET;

Each output can be configured as buck or boost mode;

Adjustable output: 0.8V to 0.85vin (buck mode) and VIN to 28V (boost mode);

In Buck mode, iout1 and iout2 are 2a and 1A respectively;

Switching frequency range: 200kHz to 2.2MHz;

Synchronous input (sync);

Clock output (CKO) is used for four phase master-slave working mode;

Independent converter enable input and power ready output;

Low standby (on / off) current IQ (7 µ a);

Internal digital soft start and soft shutdown;

Output short circuit protection and maximum duty cycle limit;

Output overvoltage protection, with automatic restart function;

Thermal shutdown;

In 32 pin TQFN package with good heat dissipation, the power consumption is 2.7W at + 70 ℃.

Responsible editor: GT

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