Zakładka z wyszukiwarką danych komponentów
Selected language     Polish  ▼
Nazwa części
         Szczegóły


DAC53401 Datasheet(Arkusz danych) 34 Page - Texas Instruments

Click here to check the latest version.
Numer części DAC53401
Szczegółowy opis  DACx3401 10-Bit and 8-Bit, Voltage-Output Digital-to-Analog Converters With Nonvolatile Memory and PMBus™ Compatible I2C Interface in Tiny 2 × 2 WSON
Pobierz  42 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Producent  TI1 [Texas Instruments]
Strona internetowa  http://www.ti.com
Logo 

 34 page
background image
SMPS
R1
R2
VFB
SENSE
PH
GND
VOUT
IN
R3
BOOT
CL
CB
L
DACx3401
VDD
VIN
DAC
SET
SET
V
I
=
R
34
DAC53401, DAC43401
SLASES7 – JULY 2019
www.ti.com
Product Folder Links: DAC53401 DAC43401
Submit Documentation Feedback
Copyright © 2019, Texas Instruments Incorporated
Typical Applications (continued)
9.2.1.2 Detailed Design Procedure
The DAC is used to set the source current of a MOSFET using the integrated unity-gain buffer, as shown in
Figure 18. The LED is connected between the power supply and the drain of the MOSFET. This configuration
allows the DAC to control or set the amount of current through the LED. The integrated buffer controls the gate-
source voltage of the MOSFET inside the feedback loop, thus compensating this drop and corresponding drift
due to temperature, current, and ageing of the MOSFET. The current set by the DAC that flows through the LED
can be calculated with Equation 6. In order to generate 0 mA to 20 mA from a 0-V to 2.4-V DAC output range, a
120-Ω RSET resistor is required. The internal reference can be selected with a span of 2x. Given a VGS of 1.2 V,
the VDD of the DAC must be at least be 3.6 V. Select a VDD of 5 V to allow variation of VGS across temperature.
When the VDD headroom is a constraint, use a bipolar junction transistor (BJT) in place of the MOSFET. BJTs
have much less VBE drop as compared to a VGS of a MOSFET. A MOSFET provides a much better match
between the current through the set register and the LED current, as compared to a BJT.
(6)
The pseudocode for getting started with an LED biasing application is as follows:
//SYNTAX: WRITE <REGISTER NAME (Hex code)>, <MSB DATA>, <LSB DATA>
//Power-up the device, enable internal reference with 2x output span
WRITE GENERAL_CONFIG(0xD1), 0x11, 0xE5
//Write DAC code (12-bit aligned)
WRITE DAC_DATA(0x21), 0x07, 0xFC
//Write settings to the NVM
WRITE TRIGGER(0xD3), 0x00, 0x10
9.2.2 Power-Supply Control
A power-supply control circuit is used for testing and tuning the output of a power converter. This testing and
tuning is done either to test the accuracy of a power supply, adjust the offset and drift of the power-supply output,
or to program a desired value at the output. Adjustable power supplies, such as LDOs and DC/DC converters
provide a feedback or adjust input that is used to set the desired output. A precision voltage-output DAC is a
good choice for controlling the power-supply output linearly. Figure 19 shows a control circuit for a switch-mode
power supply (SMPS) using DACx3401. Typical applications of power-supply control are test and measurement,
communications equipment, and general-purpose power-supply modules.
Figure 19. Power-Supply Control
9.2.2.1 Design Requirements
Power supply nominal output: 3.3 V
Reference voltage of the converter (VFB): 0.6 V
Margin: ±10% (that is, 2.97 V to 3.63 V)
DAC output range: 1.8 V
Nominal current through R1 and R2: 100 µA




Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39  40  41  42 


Datasheet Download




Link URL

Czy Alldatasheet okazała się pomocna?  [ DONATE ]  

O Alldatasheet   |   Reklama   |   Kontakt   |   Polityka prywatności   |   Dodaj do ulubionych   |   Linki   |   Lista producentów
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  , Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp  |   Russian : Alldatasheetru.com
Korean : Alldatasheet.co.kr   |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com  |   Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl