ES51998(60000counts)
DMM Analog front end/Insulation
2.11 Insulation resistance measurement mode
The ES51998 is built-in analog switches network to support the insulation resistance
measurement mode. By implementation of external high voltage source, the insulation
resistance could be obtained from SADC output of ES51998 and calculated by
microprocessor easily. The insulation mode is separated into two modes which are
insulation V mode and insulation R mode which are described below.
Insulation V mode configuration
F3
F2
F1
F0
IRV
AC
Measurement mode
Read data bytes
1
1
1
1
1
0/1
Insulation (DC/AC) V mode D0(0:18)
Note1: D0 is binary format. ASIGN is the sign bit D0.
Insulation V mode
MCU control
HV OFF (Discharging mode)
PTC
10MΩ
VA
VADC
VR2
VR3
VR4
VR5
MCU control
1.11MΩ 101KΩ 10.01KΩ 1KΩ
VDUT = VA- VB = k * VADC
VB
Q1
IRVG
Active in insulation V mode
Note: The on-resistance of internal analog switches could be omitted.
ver. 1.7
24
12/01/12