LTC1706EMS-81 Linear Technology, LTC1706EMS-81 Datasheet - Page 5

• Manufacturer Part Number: LTC1706EMS-81
• Description: IC VID VOLTAGE PROGRAMMER 10MSOP
• Manufacturer: Linear Technology

Specifications of LTC1706EMS-81

• Applications: VID Voltage Programmer
• Voltage - Supply: 2.7 V ~ 5.5 V
• Current - Supply: 0.1µA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Voltage - Input: -

OPERATIO
BLOCK DIAGRA
The LTC1706-81 is a precision resistive divider designed
specifically for use with an entire family of Linear
Technology Corporation DC/DC switching regulators with
0.8V internal reference and feedback voltage. The
LTC1706-81 produces an output voltage ranging from
1.3V to 2.05V in 50mV steps and from 2.1V to 3.5V in
100mV steps by closing the loop between the output
voltage sense and the feedback input of the regulator with
the appropriate resistive divider network.
The “top” feedback resistor, R
SENSE and FB, is typically 20k and is not modified by the
state of the VID program inputs.
The “bottom” feedback resistor, R
fied by the five VID inputs and is precisely ratioed to R
VID0
VID1
VID2
VID3
U
1
2
3
4
V
V
V
V
CC
CC
CC
CC
W
40k
40k
40k
40k
FB1
FB2
, connected between
, however, is modi-
VID4
7
FB1
V
CC
.
40k
VID Programming
A list of programmed inputs and their corresponding
output voltages is shown in Table 1. Programming is
accomplished by applying the proper voltage (or float
condition) on the five digital VID inputs. VID4 is the range
bit that puts the output voltage in either the 1.3V to 2.05V
range or the 2.1V to 3.5V range. In either range, VID3 is the
most significant bit (MSB) and VID0 is the least significant
bit (LSB).
In the lower range (VID4 = 0), when the four VID inputs are
low or grounded, the regulator output voltage is set to
2.05V. Each increasing binary count is equivalent to a
decrease of 50mV in the output voltage. Therefore, to
obtain a 1.3V output, the four VID inputs should be
floating, or high.
CONTROL
SWITCH
LOGIC
V
CC
5
R
R
FB1
FB2
LTC1706-81
10
6
9
1706-81 BD
SENSE
FB
GND
5