The TPS54040 device is a 42-V 0

TPS54040-Q1

Manufacturer Part NumberTPS54040-Q1
DescriptionThe TPS54040 device is a 42-V 0
ManufacturerTexas Instruments
TPS54040-Q1 datasheet
 


Specifications of TPS54040-Q1

Iout(max)(a)0.5Vin(min)(v)3.5
Vin(max)(v)42Vout(min)(v)0.8
Vout(max)(v)39Iq(typ)(ma)0.116
Switching Frequency(max)(khz)2500Switch Current Limit(typ)(a)0.6
TopologyBuck,Inverting Buck-BoostOperating Temperature Range(c)-40 to 125
Pin/package10MSOP-PowerPAD, 10SONDuty Cycle(max)(%)95
Regulated Outputs(#)1  
1
2
3
4
5
6
7
8
9
10
11
Page 11
12
Page 12
13
Page 13
14
Page 14
15
Page 15
16
Page 16
17
Page 17
18
Page 18
19
Page 19
20
Page 20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Page 15/51

Download datasheet (2Mb)Embed
PrevNext
www.ti.com
DETAILED DESCRIPTION (continued)
Vout
0.8V
-
æ
ö
R1 = R2
´ ç
÷
0.8 V
è
ø
Enable and Adjusting Undervoltage Lockout
The TPS54040 is disabled when the VIN pin voltage falls below 2.5 V. If an application requires a higher
undervoltage lockout (UVLO), use the EN pin as shown in
the two external resistors. Though it is not necessary to use the UVLO adjust registers, for operation it is highly
recommended to provide consistent power up behavior. The EN pin has an internal pull-up current source, I1, of
0.9μA that provides the default condition of the TPS54040 operating when the EN pin floats. Once the EN pin
voltage exceeds 1.25V, an additional 2.9μA of hysteresis, Ihys, is added. This additional current facilitates input
voltage hysteresis. Use
Equation 2
input start voltage.
Figure 28. Adjustable Undervoltage Lockout (UVLO)
V
-
V
START
STOP
R1
=
I
HYS
V
ENA
R2
=
V
V
-
START
ENA
I
+
1
R1
Another technique to add input voltage hysteresis is shown in
resistance values are high from the previous method and a wider voltage hysteresis is needed. The resistor R3
sources additional hysteresis current into the EN pin.
Copyright © 2010–2011, Texas Instruments Incorporated
Figure 28
to set the external hysteresis for the input voltage. Use
TPS54040
VIN
Ihys
I1
R 1
2.9 A
m
0.9 A
m
+
R 2
EN
1.25 V
-
Figure
TPS54040
VIN
Ihys
R 1
I1
2.9 A
m
0.9 A
m
+
R 2
EN
1.25 V
-
VOUT
R3
Figure 29. Adding Additional Hysteresis
TPS54040-Q1
SLVSA26C – JANUARY 2010 – REVISED AUGUST 2011
to adjust the input voltage UVLO by using
Equation 3
to set the
29. This method may be used, if the
(1)
(2)
(3)
15