JAJSGG2C October 2018 – June 2019 ADS125H02
Figure 102 illustrates a 5-V to ±15-V DC/DC converter for use with the device. The DC/DC converter generates ±15-V supply voltages from 5-V power. The SN6505B is a push-pull driver that drives the transformer primary from 5-V power. The typical switching frequency of the driver is 424 kHz, and when combined with the driver spread-spectrum clocking operation, reduces interference to the ADC as well as system-level EMI emissions. The secondary voltage of the 2:1 step-up transformer is half-wave rectified in a configuration that quadruples the 5-V primary voltage to generate output voltages of 20 V and –20 V. The rectified voltages are regulated by the TPS7A39 high-PSRR, dual positive and negative regulator to provide the ±15-V supply voltages.