IC STEP-DOWN SWIFT CONV 10-MSOP

TPS54040DGQ

Manufacturer Part NumberTPS54040DGQ
DescriptionIC STEP-DOWN SWIFT CONV 10-MSOP
ManufacturerTexas Instruments
SeriesSWIFT™, Eco-Mode™
TypeStep-Down (Buck)
TPS54040DGQ datasheet
 


Specifications of TPS54040DGQ

Internal Switch(s)YesSynchronous RectifierNo
Number Of Outputs1Voltage - Output0.8 ~ 39 V
Current - Output500mAFrequency - Switching100kHz ~ 2.5MHz
Voltage - Input3.5 ~ 42 VOperating Temperature-40°C ~ 150°C
Mounting TypeSurface MountPackage / Case10-MSOP Exposed Pad, 10-HMSOP, 10-eMSOP
Mounting StyleSMD/SMTDuty Cycle (max)98 %
Input / Supply Voltage (max)42 VInput / Supply Voltage (min)3.5 V
Maximum Operating Temperature+ 150 CMinimum Operating Temperature- 40 C
Output Current0.5 AOutput Voltage0.8 V to 39 V
Supply Current116 uASwitching Frequency2500 KHz
Dc To Dc Converter TypeStep DownPin Count10
Input Voltage42VSwitching Freq2500KHz
Package TypeHTSSOP EPOutput TypeAdjustable
Switching RegulatorYesMountingSurface Mount
Input Voltage (min)3.5VOperating Temperature ClassificationAutomotive
Lead Free Status / RoHS StatusLead free / RoHS CompliantPower - Output-
Other names296-24228-5  
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Adjusting the Output Voltage
The output voltage is set with a resistor divider from the output node to the VSENSE pin. It is recommended to
use 1% tolerance or better divider resistors. Start with a 10 kΩ for the R2 resistor and use the
calculate R1. To improve efficiency at light loads consider using larger value resistors. If the values are too high
the regulator will be more susceptible to noise and voltage errors from the VSENSE input current will be
noticeable
-
æ
ö
Vout
0.8V
´ ç
R1 = R2
÷
è
ø
0.8 V
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
0.9 A that provides the default condition of the TPS54040 operating when the EN pin floats. Once the EN pin
voltage exceeds 1.25V, an additional 2.9 A 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 © 2009, Texas Instruments Incorporated
DETAILED DESCRIPTION (continued)
Figure 28
to set the external hysteresis for the input voltage. Use
TPS54040
VIN
Ihys
I1
R 1
2.9 A
0.9 A
m
+
R 2
EN
-
1.25 V
Figure
Product Folder Link(s):
TPS54040
TPS54040
SLVS918 – MARCH 2009
Equation 1
to adjust the input voltage UVLO by using
Equation 3
m
29. This method may be used, if the
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to
(1)
to set the
(2)
(3)
15