Datasheet

LTC6104
6
6104f
PIN FUNCTIONS
TYPICAL PERFORMANCE CHARACTERISTICS
Step Response Falling Edge PSRR vs Frequency
OUT (Pin 1): Current Output. OUT will source or sink a
current that is proportional to the sense voltage into an
external resistor. A voltage reference is required to provide
the proper positive offset voltage so that the output can
swing both positive and negative.
V
–
(Pin 4): Negative Supply (or Ground for Single-Supply
Operation).
+INB/V
S
(Pin 5): The positive input of the internal sense
amplifi er B. It also works as the positive supply input.
Supply current is drawn through this pin.
–INB (Pin 6): The negative input of the internal sense
amplifi er B. The internal sense amplifi er will drive –INB
to the same potential as +INB when V
SENSE
is negative.
A resistor (R
IN
) tied from one end of R
SENSE
to –INB sets
the output current I
OUT
= V
SENSE
/R
IN
. V
SENSE
is the voltage
developed across the external R
SENSE
(Figure 1).
–INA (Pin 7): The negative input of the internal sense
amplifi er A. The internal sense amplifi er will drive –INA
to the same potential as +INA when V
SENSE
is positive. A
resistor (R
IN
) tied from one end of R
SENSE
to –INA sets
the output current I
OUT
= V
SENSE
/R
IN
.
+INA (Pin 8): The positive input of the internal sense
amplifi er A.
Step Response Falling Edge
TIME (1µs/DIV)
7V
V
S
– 50mV
V
S
+ 50mV
4.5V
2V
6104 G20
V
SENSE
–
T
A
= 25°C
V
S
= 12V
R
IN
= 100Ω
R
OUT
= 5k
V
SENSE
+
= V
S
V
REF
= 4.5V
V
OUT
FREQUENCY (Hz)
PSRR (dB)
0.1 1 10 100 1k 10k 100k 1M
6104 G20
160
140
120
100
80
60
40
20
0
R
IN
= 100Ω
R
OUT
= 5k
C
OUT
= 5pF
GAIN = 50
I
OUTDC
= 100µA
V
INAC
= 50mV
P-P
V
+
= 12V
V
+
= 4V
TIME (1µs/DIV)
5.5V
6V
0.5V
1V
6104 G19
V
SENSE
–
I
OUT
= –100µA
I
OUT
= 0µA
T
A
= 25°C
V
S
= 12V
R
IN
= 100Ω
R
OUT
= 5k
V
SENSE
+
= V
S
V
REF
= 6V
∆V
SENSE
–
= 100mV
V
OUT