Description
The Intersil ICL7139 and ICL7149 are high performance, low power, auto-ranging digital multimeter lCs. Unlike other autoranging multimeter ICs, the ICL7139 and ICL7149 always display the result of a conversion on the correct range. There is no “range hunting” noticeable in the display. The unit will autorange between the four different ranges. A manual switch is used to select the 2 high group ranges. DC current ranges are 4mA and 40mA in the low current group, and 400mA and 4A in the high current group. Resistance measurements are made on 4 ranges, which are divided into two groups. The low resistance ranges are 4/40kΩ. The high resistance ranges are 0.4/4MΩ. Resolution on the lowest range is 1Ω.

Features
• 13 Ranges - ICL7139
   - 4 DC Voltage 400mV, 4V, 40V, 400V
   - 1 AC Voltage 400V
   - 4 DC Current 4mA, 40mA, 400mA, 4A
   - 4 Resistance 4kΩ, 40kΩ, 400kΩ, 4MΩ
• 18 Ranges - ICL7149
   - 4 DC Voltage 400mV, 4V, 40V, 400V
   - 2 AC Voltage with Optional AC Circuit
   - 4 DC Current 4mA, 40mA, 400mA, 4A
   - 4 AC Current with Optional AC Circuit
   - 4 Resistance 4kΩ, 40kΩ, 400kΩ, 4MΩ
• Autoranging - First Reading is Always on Correct Range
• On-Chip Duplex LCD Display Drive Including Three Decimal Points and 11 Annunciators
• No Additional Active Components Required
• Low Power Dissipation - Less than 20mW - 1000 Hour Typical Battery Life
• Display Hold Input
• Continuity Output Drives Piezoelectric Beeper
• Low Battery Annunciator with On-Chip Detection
• Guaranteed Zero Reading for 0V Input on All Ranges