5.0 TC7117/TC7117A POWER
SUPPLIES
The TC7117/TC7117A are designed to operate from
±5V supplies. However, if a negative supply is not avail-
able, it can be generated with a TC7660 DC-to-DC con-
verter and two capacitors. Figure 5-1 shows this
application.
In selected applications, a negative supply is not
required. The conditions for using a single +5V supply
are:
1. The input signal can be referenced to the center
of the Common mode range of the converter.
2. The signal is less than ±1.5V.
3. An external reference is used.
+5V
35
V+ VREF+ 36
LED
Drive
32
TC7117 COM
TC7117A
VIN+
31
+
8
VIN- 30
VIN
–
2
21
+
10μF
TC7660
4
V- GND
5 (-5V) 26
3+
10μF
FIGURE 5-1:
Negative Power Supply
Generation with TC7660
TC7116/A/TC7117/A
2002-2012 Microchip Technology Inc.
DS21457D-page 13