LT1054_15 Datasheet, PDF (13/33 Pages) Linear Technology – Switched-Capacitor Voltage Converter with Regulator

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8 Application and Implementation
LT1054
SLVS033G – FEBRUARY 1990 – REVISED JULY 2015
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The negative voltage converting and regulating ability of the LT1054 make this device optimal across a wide
range of applications. As it is a regulator, there are many general design considerations that must be taken into
account. Below will describe what to consider for using this device as a basic voltage inverter/regulator. This is
the most common application for the LT1054 and the fundamental building block for the applications shown in
System Examples.
8.2 Typical Application
+
10 μF
FB/SD
8
V_CC
2
CAP+
7
OSC
LT1054
3
6
GND
V_REF
4
CAP−
5
V_OUT
V_IN
+
2 μF
R1
20 kΩ
R2
V_OUT
+
0.002 μF
+
100 μF
æ
ö
R2
=
ç
R1ç
ççè
V_OUT
V_{REF - 40}
2
mV
+
÷
1÷
÷÷ø
=
20
kW
æ
ççè
V_OUT
1.21 V
+
ö
1_÷÷ø
Pin numbers shown are for the P package.
Figure 15. Basic Voltage Inverter/Regulator
8.2.1 Design Requirements
For this design example, use the parameters listed in Table 2 as the input parameters.
Table 2. Design Parameters
Design Parameter
Input Voltage Range
V_OUT
I_OUT
Example Value
3.5V to 15V
-5V
100mA
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