LTC1099_15 Datasheet, PDF (1/16 Pages) Linear Technology – High Speed 8-Bit A/D Converter with Built-In Sample-and-Hold

FEATURES
s _{Built-In Sample-and-Hold}
s _{No Missing Codes}
s _{No User Trims Required}
s _{All Timing Inputs Edge Sensitive for Easy Processor}
Interface
s _{Fast Conversion Time: 2.5µs}
s _{Latched Three-State Outputs}
s _{Single 5V Operation}
s _{No External Clock}
s _{Overflow Output Allows Cascading}
s _{TC Input Allows User Adjustable Conversion Time}
s _{0.3" Wide 20-Pin PDIP}
U
KEY SPECIFICATIO S
s _{Resolution: 8-Bits}
s _{Conversion Time: 2.5µs (RD Mode)}
2.5µs (WR/RD Mode)
s _{Slew Rate Limit (Internal S/H): 2.5V/µs}
s _{Low Power: 75mW Max}
s _{Total Unadjusted Error}
LTC1099: ±1 LSB
LTC1099A: ±0.75 LSB
LTC1099
High Speed 8-Bit A/D
Converter with Built-In
Sample-and-Hold
DESCRIPTIO
The LTC^®1099 is a high speed microprocessor compatible
8-bit analog-to-digital converter (A/D). An internal sample-
and-hold (S/H) allows the A/D to convert inputs up to the
full Nyquist limit. With a conversion rate of 2.5µs, this
allows 156kHz 5V_P-P input signals or slew rates as high as
2.5V/µs, to be digitized without the need for an external
S/H.
Two modes of operation, Read (RD) mode and Write-Read
(WR-RD) mode, allow easy interface with processors. All
timing is internal and edge sensitive which eliminates the
need for external pulse shaping circuits. The Stand-Alone
(SA) mode is convenient for those applications not involv-
ing a processor.
Data outputs are latched with three-state control to allow
easy interface to a processor data bus or I/O port. An
overflow output (OFL) is provided to allow cascading for
higher resolution.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
V_IN
SAMPLE
HOLD
Infinite Hold Time Sample-and-Hold (T_ACQ = 240ns)
5V
15V
10k
12
20
REF⁺ V_CC
LTC1099
7
MODE
DB7 ¹⁷
1
1
6
V_IN
WR/RDY
DB6
DB5
DB4
DB3
16
15
14
5
2
3
4
5
8 _RD
DB2 ⁴
DB1 ³
6
7
13
DB0 ^{2 8}
CS
GND REF ^–
10
11 ^10k
14
REF ⁺
B1
B2
B3
B4
B5
B6
B7
B8
REF ^–
15
20
V⁺
AM6012
V^–
17
18
I_O
I_O
19
2.5k
2₊
7
LT1022
3_–
4
–15V
6
V_OUT
1099 TA01
Signal-to-Noise Ratio (SNR) vs Input Frequency
– 36
T_A = 25°C
– 38
T_C = 2.5µs
– 40
– 42
– 44
– 46
– 48
– 50
– 52
1
10
INPUT FREQUENCY (kHz)
100
1099 G08
1