CM3702

• Low noise regulator with integrated charge pump voltage-booster
• 5V output with input voltage as low as 3.0V
• Charge pump can also power external LDO
• Low noise in 20Hz to 20kHz audio band
• Up to 200mA continuous output current
• Low operating and shutdown currents
• Stable with low-ESR ceramic or tantalum capacitors
• 10-lead MSOP package
• Lead-free version available

The CM3702 low-noise charge pump LDO regulator is designed to provide accurate and "clean" power to a subsystem, e.g an LED driver, audio codec or flash memory. The 5V output provides up to 100mA continuous current for input voltages from 3.0V to 5.5V, and up to 200mA for a narrower range. This is accomplished with an integrated charge pump that boosts the input voltage before feeding it to an internal LDO linear regulator. The charge pump is designed to maintain a nominal 0.8V differential between the input and output of the LDO regulator. This allows the LDO regulator to operate with good power supply ripple rejection across the audio band while maintaining good power efficiency. The charge pump works with two external capacitors and operates at 250kHz, well outside the audible frequency band. In addition, separate analog and digital ground pins are provided for the charge pump and the rest of the circuitry to eliminate ground noise feed-through from the charge pump to the regulated output.

The CM3702 is fully protected, offering both overload current limiting and high temperature thermal shutdown.

Two enable inputs CM3702 provide flexibility in powering down the device. For maximum power saving in shutdown, both the charge pump and LDO regulator should be disabled. For applications that require the 5V output to be re-established with minimum delay after shutdown, the charge pump can be left enabled while the regulator is disabled. This avoids the delay that may otherwise be required for the charge pump to reach full operating voltage after being disabled. The CMOS LDO regulator features low quiescent current even at full load, making it very suitable for power sensitive applications.

A bandgap reference bypass pin is provided to further minimize noise by connecting an external capacitor between this pin and ground. Another, external, regulator can be connected to the charge pump output pin CS, if required.

The CM3702 is available in a 10-lead MSOP package, with optional lead-free finishing and is ideal for space critical applications.

Note: Some of the devices listed here have suggested replacements available. Please see additional information at the end of this page.