Datasheet
LTC2754
11
2754f
BLOCK DIAGRAM
DAC B
16-BIT WITH
SPAN SELECT
16
3
DATA REGISTERS
SPAN REGISTERS
INPUT REG
16
3
DATA REGISTERS
INPUT REG
SPAN REGISTERS
DAC REG
DAC REG
39
40
41
42
43
44
45
38
46
21
29
22
23
24
R
OFSB
REFB
R
INB
R
INC
SROGNDSROSCKSDIS0S1S2M-SPAN CS/LD
LDACCLRRFLAG
GE
ADJB
R
COMB
I
OUT1B
I
OUT2B
V
OSADJB
V
OSADJC
GE
ADJC
R
FBB
I
OUT1C
R
FBC
R
OFSC
R
COMC
REFC
I
OUT2C
DAC C
16-BIT WITH
SPAN SELECT
25
26
27
28
36765303133343532
16
3
DATA REGISTERS
SPAN REGISTERS
DAC REG
DAC REG
INPUT REG
16
3
DATA REGISTERS
INPUT REG
SPAN REGISTERS
DAC REG
DAC REG
2
1
52
51
50
49
48
3
47
20
12
19
18
17
R
OFSA
REFA
R
INA
R
IND
GE
ADJA
R
COMA
I
OUT1A
I
OUT2A
V
OSADJA
V
OSADJD
GE
ADJD
R
FBA
I
OUT1D
R
FBD
R
OFSD
R
COMD
REFD
I
OUT2D
16
15
14
13
DAC A
16-BIT WITH
SPAN SELECT
DAC D
16-BIT WITH
SPAN SELECT
POWER-ON
RESET
9
GND
4, 11, 37
8
V
DD
10
INPUT REG
INPUT REG
INPUT REG
INPUT REG
DAC REG
DAC REG
DAC B
16-BIT WITH
SPAN SELECT
CONTROL AND READBACK LOGIC
2754 BD
LTC2754-16
2.56M 2.56M
2.56M 2.56M
20k
20k
20k
20k
20k
20k
20k
20k
R
OFSA
(Pin 50): Bipolar Offset Network for DAC A. This
pin provides the translation of the output voltage range for
bipolar spans. Accepts up to ±15V; for normal operation
tie to the positive reference voltage at R
INA
(Pin 2). The
impedance looking into this pin is 20k to ground.
REFA (Pin 51): Inverted Reference Voltage for DAC A, with
internal connection to the reference inverting resistor. The
20k resistor is connected internally from REFA to R
COMA
.
For normal operation tie this pin to the output of reference
inverting amplifi er (see Typical Applications). Typically – 5V;
accepts up to ±15V. The impedance looking into this pin
is 10k to ground (R
INA
and R
COMA
fl oating).
R
COMA
(Pin 52): Center Tap Point for Reference Amplifi er
Inverting Resistors. The 20k reference inverting resistors
are connected internally from R
INA
to R
COMA
and from
R
COMA
to REFA, respectively (see Block Diagram). For
normal operation tie R
COMA
to the negative input of external
reference inverting amplifi er (see Typical Applications).
Exposed Pad (Pin 53): Ground. The Exposed Pad must
be soldered to the PCB.
PIN FUNCTIONS