TPS65055 Datasheet, PDF (9/39 Pages) Texas Instruments – 2.25 MHz Dual Step-Down Converter With 4 Low Input Voltage LDOs

TPS65055
www.ti.com.......................................................................................................................................................................................... SLVS844 – SEPTEMBER 2008
PARAMETER MEASUREMENT INFORMATION
The measurements for the graphs were taken using the EVM in the configuration shown in the functional block
diagram. The inductors used were Coilcraft LPS3010.
TABLE OF GRAPHS
TYPICAL CHARACTERISTICS
η
Efficiency DCDC1 (V_O = 2.1 V)
η
Efficiency DCDC1 (V_O = 2.1 V)
η
Efficiency DCDC2 (V_O = 1.575 V)
η
Efficiency DCDC2 (V_O = 1.575 V)
η
Efficiency DCDC2 (V_O = 1.2 V)
η
Efficiency DCDC2 (V_O = 1.2 V)
Output voltage ripple in PFM mode
Output voltage ripple in PWM mode
Startup timing DCDC1, DCDC2, LDO1
Startup timing LDO1, LDO2, LDO3, LDO4
Load transient response DCDC1; PWM
Load transient response DCDC1; PFM
Load transient response DCDC2; PWM
Load transient response DCDC2;PFM
Line transient response DCDC1 (V_O = 2.1 V)
Line transient response DCDC2 (V_O = 1.2 V)
Load transient response LDO1
Load transient response LDO4
Line transient response LDO1
vs Load current / PWM mode
vs Load current / PFM mode
vs Load current / PWM mode
vs Load current / PFM mode
vs Load current / PWM mode
vs Load current / PFM mode
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
Scope plot
FIGURE
1
2
3
4
5
6
7
8
9
10
11
12
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15
16
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18
19
EFFICIENCY DCDC1 (V_O = 2.1 V)
vs
LOAD CURRENT / PWM MODE
100
90
T_A = 25°C,
PWM Mode,
80 ^{VO = 2.1 V}
3V
70
60
3.6 V
50
4.2 V
40
30
5V
20
10
0
0.0001
0.001
0.01
0.1
1
I_O - Output Current - A
Figure 1.
EFFICIENCY DCDC1 (V_O = 2.1 V)
vs
LOAD CURRENT / PFM MODE
100
90
80
3V
70
3.6 V
60
4.2 V
50
5V
40
30
20
10
0
0.0001
T_A = 25°C,
PWM/PFM Mode,
V_O = 2.1 V
0.001
0.01
0.1
1
I_O - Output Current - A
Figure 2.
Copyright © 2008, Texas Instruments Incorporated
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