4
LTC1850/LTC1851
18501f
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IH
High Level Input Voltage V
DD
= 5.25V ● 2.4 V
V
IL
Low Level Input Voltage V
DD
= 4.75V ● 0.8 V
I
IN
Digital Input Current V
IN
= 0V to V
DD
● ±5 µA
C
IN
Digital Input Capacitance 2pF
V
OH
High Level Output Voltage V
DD
= 4.75V, I
O
= –10µA 4.5 V
V
DD
= 4.75V, I
O
= –200µA ● 4.0 V
V
OL
Low Level Output Voltage V
DD
= 4.75V, I
O
= 160µA 0.05 V
V
DD
= 4.75V, I
O
= 1.6mA ● 0.10 0.4 V
I
OZ
Hi-Z Output Leakage D11 to D0, AD
OUT
, A1
OUT
, A2
OUT
, DIFF
OUT
V
OUT
= 0V to V
DD
, CS High ● ±10 µA
C
OZ
Hi-Z Capacitance D11 to D0, AD
OUT
, A1
OUT
, A2
OUT
, DIFF
OUT
CS High (Note 9) ● 15 pF
I
SOURCE
Output Source Current V
OUT
= 0V –20 mA
I
SINK
Output Sink Current V
OUT
= V
DD
30 mA
The ● denotes the specifications which apply over the
full operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
DIGITAL I PUTS A D DIGITAL OUTPUTS
UU
PARAMETER CONDITIONS MIN TYP MAX UNITS
REFOUT Output Voltage I
OUT
= 0 2.48 2.50 2.52 V
REFOUT Output Temperature Coefficient I
OUT
= 0 ±15 ppm/°C
REFOUT Line Regulation 0.01 LSB/V
Reference Buffer Gain V
REFCOMP
/V
REFIN
1.636 1.638 1.640 V/V
REFCOMP Output Voltage External 2.5V Reference 4.090 4.096 4.100 V
Internal 2.5V Reference 4.060 4.096 4.132 V
REFCOMP Impedance REFIN = V
DD
6.4 kΩ
T
A
= 25°C. (Notes 5, 6)
I TER AL REFERE CE
UU U
LTC1850 LTC1851
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
SNR Signal-to-Noise Ratio 47kHz Input Signal
Unipolar, PGA = 0 61.6 71 dB
Unipolar, PGA = 1 61.7 72 dB
Bipolar, PGA = 0 61.6 71 dB
Bipolar, PGA = 1 61.7 72 dB
S/(N+D) Signal-to-(Noise + Distortion) Ratio 47kHz Input Signal
Unipolar, PGA = 0 61.0 70 dB
Unipolar, PGA = 1 61.0 71 dB
Bipolar, PGA = 0 61.0 71 dB
Bipolar, PGA = 1 61.2 72 dB
THD Total Harmonic Distortion 47kHz Input Signal,
Unipolar, PGA = 0 First 5 Harmonics –76 –80 dB
Unipolar, PGA = 1 –78 –82 dB
Bipolar, PGA = 0 –81 –87 dB
Bipolar, PGA = 1 –80 –86 dB
SFDR Spurious-Free Dynamic Range 47kHz Input Signal
Unipolar, PGA = 0 74 82 dB
Unipolar, PGA = 1 80 86 dB
Bipolar, PGA = 0 84 90 dB
Bipolar, PGA = 1 82 88 dB
DY A IC ACCURACY
U
W
(Note 5)