LTC7106
A 7-Bit Current DAC with
PMBus Interface
FEATURES
nn ±0.8% IDAC Positive Output Current Accuracy
(Over Temp)
nn ±1.5% IDAC Negative Output Current Accuracy
(Over Temp)
nn PMBus/I2C Compliant Serial Interface
nn Input Voltage Range: 2.5V to 5.5V
nn High Impedance at IDAC Output When Disabled
nn Wide IDAC Operation Voltage (0.4V to 2.0V)
nn 7-Bit Programmable DAC Output Current for DC/DC
VOUT Control
nn Wide Range IDAC Output Current: ±16μA to ±256μA
nn Programmable Slew Rate: 500ns ~ 3ms per Bit
nn Available in a 10-Lead (3mm × 2mm) DFN Package
APPLICATIONS
nn General Purpose Power Systems
nn Telecom Systems
nn Industrial Applications
DESCRIPTION
The LTC®7106 is a precision, PMBus controlled, bidi-
rectional current digital-to-analog converter that adjusts
the output voltage of any conventional VFB referenced
regulator. The LTC7106 can work with the vast majority
of power management controllers or regulators to enable
digital control of the output voltage. Internal power-on
reset circuitry keeps the DAC output current at zero
(high impedance IDAC) until a valid write takes place.
Features include a range bit for easy interfacing to almost
any impedance resistor divider, and an open-drain GPO
output for controlling the Run or Enable pin of the DC/
DC regulator. For most applications, the current DAC error
is significantly attenuated with proper design. See more
detail about VOUT accuracy in the Applications Information
section of this data sheet. The LTC7106 is supported by
the ADI LTpowerPlay® development tool with graphical
user interface (GUI).
All registered trademarks and trademarks are the property of their respective owners.
TYPICAL APPLICATION
VIN VIN
SW
DC/DC
RUN
VFB
L1
VREF
RFB1
VOUT
C2
330µF
(0.4V to 2V)
RFB2
VDD
2.5V
TO 5.5V
C1
1µF 10k 10k 10k
R3 R2 R1
PMBus INTERFACE
SDA
SCL
ALERT
SDA
SCL
ALERT
GND
R4
10k
0μA TO 63μA
VDD EN GPO
LTC7106
IDAC
ASEL0
VDD
ASEL1
7106 TA01a
–64μA TO 0μA
Margin High and Margin Low
CIRCUIT OF FIGURE 11
VOUT
5V/DIV
VOUT = 24V
IDAC = 0μA
IDAC = –40μA
IDAC = 40μA
EN
2V/DIV
100ms/DIV
7106 TA01b
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For more information www.analog.com
Rev A
1