ax88796blf ASIX Electronics Corporation, ax88796blf Datasheet - Page 81

• Manufacturer Part Number: ax88796blf
• Description: Low-pin-count Non-pci 8/16-bit 10/100m Fast Ethernet Controller
• Manufacturer: ASIX Electronics Corporation

Appendix B: Disable AX88796B voltage regulator
system have 1.8V power source already, user may like to disable AX88796B voltage regulator and use the existing
1.8V power source (probably a higher efficiency version). In that case, user can connect VCC3R3 (pin-10) and
GND3R3 (pin-11) to ground, keep V18F (pin-9) open, and set REGSTB bit of PMR register (see Page3 Offset 0BH
bit-4 in section 5.1.56 Power Management Register (PMR)) to 0 (i.e. logic "low") to avoid the leakage current.
Please refer to below picture for details.
AX88796B integrates an on-chip 3.3V to 1.8V voltage regulator for single-power supply system design. If the
Logic “low”
GND
REGSTB
VCC3R3
GND3R3
AX88796B
VCC18A
VCCK
V18F
81
AX88796BLF / AX88796BLI
Supply Digital 1.8V from existing power source
on system
AX88796B will disable the on-chip voltage
regulator when the VCC3R3 pin was
connected to GND.
Supply Analog 1.8V from existing power
source on system
Keep NC without loading
ASIX ELECTRONICS CORPORATION