ia3513 integration, ia3513 Datasheet - Page 9

• Manufacturer Part Number: ia3513
• Description: Headset Voice And Power Solution
• Manufacturer: integration

DC-DC CONVERTER
Description
The DC-DC is a 100 mA voltage mode controlled buck converter with internal power switches. It has the flexibility of several
fixed output voltages and pulse skipping for low power operation. The following are the key considerations for the design:
Functional Block Diagram
The internal block diagram for the DC-DC is shown below. The PWM voltage control loop comprises: the feedback DAC, the
sigma delta modulator, digital PID compensator, pulse width modulator (PWM), gate drivers, and power FETs. When light loads
are sensed and pulse skipping is enabled, the loop control is shut down and the output switches are turned off. The output
voltage is then monitored by the comparator and the loop is re-enabled when the output voltage drops below a low threshold
limit. During the shutdown time, everything except the output sensing comparator is disabled. Supply switch over-current
protection is provided to protect the chip against overloads. Soft-start is provided by ramping up the internal reference from zero
to the target value after power on reset.
• 700 mΩ PMOS power switch
• 500 mΩ NMOS synchronous rectifier
• Internal PID Loop Compensation
• Internal Soft Start
• Low quiescent current in both standby & PWM modes, non-switching
• Pulse skipping for high efficiency at light loads
• Anti-ring FET for low noise during pulse skipping & bulk diode protection
• Internal or external oscillator
• 1MHz switching frequency
• 10 mVrms output ripple
• 20 us settling time
• Over current protected
Top Level Block Diagram of the DC-DC Buck Converter
L1
C6
IA3513
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