difference between LTC2672 and LTC2662

Hi dapan0518 ,

They are indeed very similar parts, here's some differences:

1.) The LTC2672 has a lower dropout voltage (0.6V at 200mA) compared to the LTC2662 (1V at 200mA)

2.) The LTC2672 operates with output supply voltages (VDDx) from 2.1V to VCC, giving it flexibility​ while LTC2662, requires VDD0-4 to be between 2.85V and V+, where V+ can be as high as 33V​

3.) Interms of tempcos LTC2672 has an internal reference with a 2.4 ppm/°C (WLCSP) or 10 ppm/°C (LFCSP) temperature coefficient.
while LTC2662 has an internal reference with a 10 ppm/°C maximum temperature coefficient.

4.) While for package details and digital interface, LTC2672 offers LFCSP and WLCSP packages, with a digital supply voltage from 1.71V to VCC while LTC2662 offers QFN package, with a digital interface operating from 1.8V to 5V.

While the LTC2672 and LTC2662 are quite similr in many aspects, the LTC2672 offers a lower dropout voltage, broader flexibility in output supply voltage, and improved internal reference stability in certain package options. These differences may make the LTC2672 a better fit for applications that benefit from lower power requirements and enhanced temperature performance, while the LTC2662 could be preferred in cases where a higher supply voltage or a different digital interface is needed.

Br,

Den

The answer is very detailed，thank you very much.

glad I could help

I have done quite a bit of testing on both chips.

The noise spectral density of the ltc2662 is ~5 nA/rtHz @ 1MHz, while the '72 variant is ~3 nA/rtHz

The '72s datasheet says that it has a lower dropout and that it can be run from 2.1V instead of 2.85V, but both chips actually can drive a laser from 2.1V just fine.

The '72 has a problem with noise in the low MHz frequencies when being run far from the max DAC span.