LTC2630-HM10 LINER [Linear Technology], LTC2630-HM10 Datasheet - Page 13

• Manufacturer Part Number: LTC2630-HM10
• Description: Single 12-/10-/8-Bit Rail-to-Rail DACs with Integrated Reference in SC70
• Manufacturer: LINER [Linear Technology]

TIMING DIAGRAM
OPERATION
The LTC2630 is a family of single voltage output DACs in
6-lead SC70 packages. Each DAC can operate rail-to-rail
referenced to the input supply, or with its full-scale volt-
age set by an integrated reference. Twelve combinations
of accuracy (12-, 10-, and 8-bit), power-on reset value
(zero or midscale), and full-scale voltage (2.5V or 4.096V)
are available. The LTC2630 is controlled using a 3-wire
SPI/MICROWIRE compatible interface.
Power-On Reset
The LTC2630-HZ/-LZ clear the output to zero scale when
power is fi rst applied, making system initialization con-
sistent and repeatable.
For some applications, downstream circuits are active
during DAC power-up, and may be sensitive to nonzero
outputs from the DAC during this time. The LTC2630
contains circuitry to reduce the power-on glitch: the
analog output typically rises less than 5mV above zero
scale during power on if the power supply is ramped
to 5V in 1ms or more. In general, the glitch amplitude
decreases as the power supply ramp time is increased.
See “Power-On Reset Glitch” in the Typical Performance
Characteristics section.
The LTC2630-HM/-LM provide an alternative reset, setting
the output to midscale when power is fi rst applied.
CS/LD
SCK
SDI
t
5
t
7
t
1
t
2
1
Figure 1. Serial Interface Timing
t
3
2
Transfer Function
The digital-to-analog transfer function is
where k is the decimal equivalent of the binary DAC
input code, N is the resolution, and V
(LTC2630-L) or 4.096V (LTC2630-H) in internal refer-
ence mode, and V
Table 1. Command Codes
*Command codes not shown are reserved and should not be used.
Command*
C3 C2 C1 C0
0
0
0
0
0
0
t
4
V
OUT IDEAL
0
0
0
1
1
1
(
3
0
0
1
0
1
1
0
1
1
0
0
1
)
=
⎛
⎝ ⎜
Write to Input Register
Update (Power up) DAC Register
Write to and Update (Power up) DAC Register
Power down
Select Internal Reference (Power-on Reset Default)
Select Supply as Reference (V
2
k
N
23
CC
⎞
⎠ ⎟
V
in Supply as reference mode.
REF
t
6
24
t
REF
10
LTC2630
REF
= V
is either 2.5V
CC
)
2630 F01
13
2630f