LTC2636IMS-HZ12#PBF Linear Technology, LTC2636IMS-HZ12#PBF Datasheet - Page 17

• Manufacturer Part Number: LTC2636IMS-HZ12#PBF
• Description: IC DAC 12-BIT OCTAL 16-MSOP
• Manufacturer: Linear Technology

Specifications of LTC2636IMS-HZ12#PBF

• Settling Time: 4.4µs
• Number Of Bits: 12
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 8
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 2.7mW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-MSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

OPERATION
The LTC2636 is a family of octal voltage output DACs
in 14-lead DFN and 16-lead MSOP packages. Each DAC
can operate rail-to-rail using an external reference, or
with its full-scale voltage set by an integrated reference.
Eighteen combinations of accuracy (12-, 10-, and 8-bit),
power-on reset value (zero-scale, mid-scale in internal
reference mode, or mid-scale in external reference mode),
and full-scale voltage (2.5V or 4.096V) are available. The
LTC2636 is controlled using a 3-wire SPI/MICROWIRE
compatible interface.
Power-On Reset
The LTC2636-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 LTC2636
contains circuitry to reduce the power-on glitch: the
analog output typically rises less than 5mV above zero-
scale during power on. 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 LTC2636-HMI/-HMX/-LMI/-LMX provide an alterna-
tive reset, setting the output to mid-scale when power is
fi rst applied. The LTC2636-LMI and LTC2636-HMI power
up in internal reference mode, with the output set to a
mid-scale voltage of 1.25V and 2.048V respectively. The
LTC2636-LMX and LTC2636-HMX power-up in external
reference mode, with the output set to mid-scale of the
external reference. Default reference mode selection is
described in the Reference Modes section.
Power Supply Sequencing
The voltage at REF (Pin 9-DFN, Pin 11-MSOP) must be
kept within the range –0.3V ≤ V
Absolute Maximum Ratings). Particular care should be
taken to observe these limits during power supply turn-
on and turn-off sequences, when the voltage at V
transition.
REF
≤ V
CC
+ 0.3V (see
CC
is in
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
LMI/-LMX/-LZ) or 4.096V (LTC2636-HMI/-HMX/-HZ) when
in Internal Reference mode, and the voltage at REF when
in External Reference mode.
Table 1. Command Codes
COMMAND*
*Command codes not shown are reserved and should not be used.
Table 2. Address Codes
ADDRESS (n)*
* Address codes not shown are reserved and should not be used.
A3
C3
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
V
OUT(IDEAL)
A2
C2
0
0
0
0
1
1
1
1
1
0
0
0
0
1
1
1
1
1
A1
C1
0
0
1
1
0
0
1
1
1
0
0
1
1
0
0
1
1
1
C0
A0
0
1
0
1
0
1
0
1
1
0
1
0
1
0
1
0
1
1
=
⎛
⎝ ⎜
Write to Input Register n
Update (Power-Up) DAC Register n
Write to Input Register n, Update (Power-Up) All
Write to and Update (Power-Up) DAC Register n
Power-Down DAC n
Power-Down Chip (All DAC’s and Reference)
Select Internal Reference (Power-Up Reference)
Select External Reference (Power-Down Internal
Reference)
No Operation
DAC A
DAC B
DAC C
DAC D
DAC E
DAC F
DAC G
DAC H
All DACs
2
k
n
⎞
⎠ ⎟
V
REF
REF
is either 2.5V (LTC2636-
LTC2636
17
2636fb