Datasheet

5
LTC2846
sn2846 2846fs
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 5V, V
IN
= 3.3V, V
SHDN
= V
IN
, unless otherwise noted. (Notes 2, 3)
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: All currents into device pins are positive; all currents out of device
are negative. All voltages are referenced to device ground unless otherwise
specified.
Note 3: All typicals are given for V
CC
= 5V, V
IN
= 3.3V, C
VCC
= C
VIN
= 10µF,
C
VDD
= 1µF, C
VEE
= 3.3µF and T
A
= 25°C.
Note 4: The Boost Regulator is specified for V
IN
= 3V unless otherwise
noted.
Note 5: Current limit guaranteed by design and/or correlation to static test.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V.28 Receiver
V
THL
Input Low Threshold Voltage (Figure 12) ● 0.8 V
V
TLH
Input High Threshold Voltage (Figure 12) ● 2V
∆V
TH
Receiver Input Hysteresis (Figure 12) ● 0 0.05 0.3 V
R
IN
Receiver Input Impedance –15V ≤ V
A
≤ 15V ● 357 kΩ
t
r
, t
f
Rise or Fall Time C
L
= 50pF (Figures 12, 16) 15 ns
t
PLH
Input to Output C
L
= 50pF (Figures 12, 16) ● 60 300 ns
t
PHL
Input to Output C
L
= 50pF (Figures 12, 16) ● 160 300 ns
Boost Switching Regulator (Note 4)
V
IN
Operating Voltage 3 3.3 3.6 V
V
FB
Feedback Voltage ● 1.230 1.255 1.280 V
I
FB
FB Pin Bias Current V
FB
= 1.255V ● 120 360 nA
I
Q
Quiescent Current V
SHDN
= 2.4V, Not Switching 4.2 6 mA
Quiescent Current in Shutdown V
SHDN
= 0V, V
IN
= 3V 0.01 1 µA
∆V
FB(LR)
Reference Line Regulation 3V ≤ V
IN
≤ 3.6V 0.01 0.05 %/V
f Switching Frequency ● 0.85 1.2 1.6 MHz
DC
MAX
Maximum Duty Cycle ● 82 90 %
I
LIM
Switch Current Limit (Note 5) 1 1.2 2 A
V
SAT
Switch V
CESAT
I
SW
= 900mA 350 mV
I
LEAK
Switch Leakage Current V
SW
= 5V 0.01 1 µA
TYPICAL PERFOR A CE CHARACTERISTICS
UW
V.11 Mode I
CC
vs Data Rate
DATA RATE (kBd)
10
I
CC
(mA)
120
130
140
2846 G04
110
100
90
100 1000
150
160
170
10000
T
A
= 25°C
DATA RATE (kBd)
10
120
I
CC
(mA)
125
130
135
140
150
100 1000
2846 G05
10000
145
T
A
= 25°C
DATA RATE (kBd)
10
30
I
CC
(mA)
35
40
45
50
60
20 40 60 80 100
2846 G06
55
T
A
= 25°C
V.35 Mode I
CC
vs Data Rate V.28 Mode I
CC
vs Data Rate