Data Sheet

ADPA7008

BIASING ADPA7008 WITH THE HMC980LP4E

analog.com

Rev. 0 | 25 of 28

Figure 75. Application Circuit Using HMC980LP4E with ADPA7008 (Internal Negative Voltage Source)

Figure 76. Application Circuit Using HMC980LP4E with ADPA7008 (External Negative Voltage Source)

HMC980LP4E BIAS SEQUENCE

When using the HMC980LP4E to control the ADPA7008, the dc

supply sequences described in the Power-Up Sequence section

and the Power-Down Sequence section are recommended to pre-

vent damage to the HMC980LP4E and the ADPA7008.

Power-Up Sequence

The power-up sequence for the HMC980LP4E is as follows:

1. Set EN = 0 V to ensure that the HMC980LP4E powers up

without turning on the VGATE and VDRAIN pins.

2. Set VDIG = 3.3 V.

3. Set S0 and S1 = 3.3 V. The Sx pins are internally pulled up to

VDIG; therefore, this step is optional

5. Set VNEG = −1.5 V. Note that this step is unnecessary if using

the internally generated negative voltage.

6. Set EN = 3.3 V, which turns on the VGATE and VDRAIN pins.