Spark Logic

ICL7660 inverting charge pump connection guide

ICL7660 inverting charge pump SOIC-8 wiring guide with power, signal assignments, and bench checks.

PDIP-8 8 contacts

SOIC-8

8 contacts Current package

Renesas / Intersil · Surface-mount narrow M8.15 outline.

1.5 to 12 V operating supply, 0 to 70 °C.

Invert a 5 V rail

Required

Fit two 10 µF capacitors rated for at least 10 V. Leave NC, LV and OSC open at 5 V.

  • Positive supply
    • V+ (8)
    • Current-limited 5 V supply
  • Ground
    • GND (3)
    • C2 positive
    • Supply return
    • Meter common
  • Flying capacitor positive
  • Flying capacitor negative
  • Negative output
C1 10 µF electrolytic between Flying capacitor positive and Flying capacitor negativeFlying capacitor positiveC1 10 µF electrolyticFlying capacitor negative
C2 10 µF electrolytic between Ground and Negative outputGroundC2 10 µF electrolyticNegative output

Bench checks

  • Check the polarized capacitor orientation. C1 positive goes to CAP+ and C2 positive goes to ground.
  • Read VOUT with respect to ground on a high-impedance meter. Expect a negative voltage approaching −5 V without a load.

Renesas / Intersil FN3072 Rev. 7.00, Figure 13 and Do’s And Don’ts.

Connection scenarios

Measure the output drop under load

Turn power off and add a 10 kΩ resistor from VOUT to ground. Use the same supply and capacitors.

  • Positive supply
    • V+ (8)
    • Current-limited 5 V supply
  • Ground
    • GND (3)
    • C2 positive
    • Supply return
    • Meter common
    • RL.1
  • Flying capacitor positive
  • Flying capacitor negative
  • Negative output
C1 10 µF electrolytic between Flying capacitor positive and Flying capacitor negativeFlying capacitor positiveC1 10 µF electrolyticFlying capacitor negative
C2 10 µF electrolytic between Ground and Negative outputGroundC2 10 µF electrolyticNegative output
RL 10 kΩ between Ground and Negative outputGroundRL 10 kΩNegative output

Bench checks

  • Expect a nominal load of about 0.5 mA. Compare the loaded voltage and ripple against the unloaded reading.

Renesas / Intersil FN3072 Rev. 7.00, Figures 13–14. The load is a fixture choice.

SOIC-8 wiring map

Highlighted contacts are used in the required step or selected circuit. Select a contact to inspect it.

Top view. Locate the package index before counting counterclockwise from pin 1.
Selected pin details

1 · NC

No connection · NC / reserved

Leave open. The ICL7660S has a different function at this position.

Renesas / Intersil FN3072 Rev. 7.00, p. 1

Electrical limits · Pin in the reference

Models and documents

The original ICL7660 and ICL7660A share the same contact functions. The ICL7660S has a frequency boost pin where this map shows NC.

ICL7660CBA
1.5 to 10 V operating supply, 0 to 70 °C.
ICL7660CBA-T
1.5 to 10 V operating supply, 0 to 70 °C.
ICL7660CBAZ
1.5 to 10 V operating supply, 0 to 70 °C.
ICL7660CBAZ-T
1.5 to 10 V operating supply, 0 to 70 °C.
ICL7660CBAZA
1.5 to 10 V operating supply, 0 to 70 °C.
ICL7660CBAZA-T
1.5 to 10 V operating supply, 0 to 70 °C.
ICL7660ACBA
1.5 to 12 V operating supply, 0 to 70 °C.
ICL7660ACBA-T
1.5 to 12 V operating supply, 0 to 70 °C.
ICL7660ACBAZA
1.5 to 12 V operating supply, 0 to 70 °C.
ICL7660ACBAZA-T
1.5 to 12 V operating supply, 0 to 70 °C.
ICL7660AIBA
1.5 to 12 V operating supply, −40 to +85 °C.
ICL7660AIBA-T
1.5 to 12 V operating supply, −40 to +85 °C.
ICL7660AIBAZA
1.5 to 12 V operating supply, −40 to +85 °C.
ICL7660AIBAZA-T
1.5 to 12 V operating supply, −40 to +85 °C.