Texas Instruments TPS769 Series, User Manual, Page: 23 / 25

Test Setup
3-5 Testing
Operation of the 1-V EVM with input voltages from 2.7 V to 3 V requires in-
creasing the bias current for the TL431. Changing R5 to 180
Ω
accomplishes
this at the expense of higher quiescent currents. Figures 3–4 and 3–5 show
the results of this modification.
Figure 3–4. Quiescent Current vs Output Current
0
2
4
6
8
10
12
14
16
0 20 40 60 80 100
QUIESCIENT CURRENT
vs
OUTPUT CURRENT
VIN = 5 V
R5=180
Ω
IO – Output Current – mA
– Quiscent Current – mA
I Q
Figure 3–5. Line Regulation from 2.7 V
1.033
1.0335
1.034
1.0345
1.035
1.0355
1.036
1.0365
1.037
1.0375
2 2.5 3 3.5
II =95.6 mA
II =12 mA
VI – Input Voltage – V
– Output V
oltage – V
V
O
4 4.5 5
R5=180
Ω
LINE REGULATION FROM 2.7 V