Datasheet

LTC3773
3
3773fb
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loop
V
FB
Feedback Voltage V
ITH
= 1.2V, 0°C ≤ T ≤ 85°C (Note 4)
0.594
0.591
0.600
0.600
0.606
0.609
V
V
I
VFB
Feedback Pin Input Current 0 ≤ V
FB
≤ 1V 15 100 nA
V
SENSEMAX
Maximum Current Sense Threshold V
FB
= 0.55V, V
TRACK
= 1V, V
SENSE
= 2.5V
65
60
75
75
85
90
mV
mV
V
FBLOADREG
Feedback Voltage Load Regulation Measured in Servo Loop (Note 4)
Δ
ITH
Voltage = 1.2V to 0.7V
Δ
ITH
Voltage = 1.2V to 2V
0.15
–0.2
0.5
–0.5
%
%
V
FBLNREG
Feedback Voltage Line Regulation V
CC
= 4.5V to 6V 0.01 %/V
g
m
Transconductance Amplifi er g
m
V
ITH
= 1.2V, Sink/Source 25μA (Note 4)
2.3 2.7 3.2 mmho
f
u
Transconductance Amplifi er GBW V
ITH
= 1.2V (Note 5) 3 MHz
A
ERR
Transconductance Amplifi er DC Gain V
ITH
= 0.8V to 1.6V
50 56 dB
V
UVR
V
CC
Undervoltage Reset
Undervoltage Hysteresis
V
CC
Ramping Positive 3.7 4.1
0.16
4.4 V
V
V
CC
V
CC
Supply Voltage
4.5 5 6 V
I
VCC
V
CC
Supply Current
Normal Mode
Shutdown
V
CC
= 5V
V
SDB
= 0V
2.8
20
4
30
mA
μA
I
VDR
V
DR
Supply Current
Normal Mode
Shutdown
V
DR
= 5V (Note 6)
V
SDB
= 0V
5
1
mA
μA
I
BOOST
V
BOOST
Supply Current
Normal Mode
Shutdown
V
BOOST
= 5V, V
SW
= 0V (Note 6)
V
SDB
= 0V
1
1
mA
μA
I
SDB
SDB Source Current
SDB1, SDB2, SDB3 Source Content
–1.5
–0.5
μA
μA
V
SDB
SDB Power Up Threshold
SDB1 Pin CH1 ON Threshold
SDB2 Pin CH2 ON Threshold
SDB3 Pin CH3 ON Threshold
Ramping Positive
0.4
1.14
1.71
2.3
1.2
1.8
2.4
1.26
1.89
2.5
V
V
V
V
Channel On Threshold Hysteresis 10 %
I
SENSE
SENSE Pins Source Current V
SENSE
+
, V
SENSE
= 1.2V, Current at Each Pin –13 –20 μA
DF
MAX
Maximum Duty Factor PLLFLTR Floats, In Dropout 97 98.5 %
TG R
UP
TG Driver Pull-Up On-Resistance TG High, I
OUT
= 100mA (Note 7) 2.2 Ω
TG R
DOWN
TG Driver Pull-Down On-Resistance TG Low, I
OUT
= 100mA (Note 7) 1.8 Ω
BG R
UP
BG Driver Pull-Up On-Resistance BG High, I
OUT
= 100mA (Note 7) 2.4
Ω
BG R
DOWN
BG Driver Pull-Down On-Resistance BG Low, I
OUT
= 100mA (Note 7) 0.9 Ω
TG/BG t
1D
Top Gate OFF to Bottom Gate ON Delay
Synchronous Switch-On Delay Time
All Controllers 50 ns
BG/TG t
2D
Bottom Gate OFF to Top Gate ON Delay
Top Switch-On Delay Time
All Controllers 50 ns
t
ON(MIN)
Minimum On-Time Tested with a Square Wave (Note 8) 130 ns
Tracking
I
TRACK
TRACK Pin Pull-Up Current V
SDB
= 5V, V
TRACK
= 0V 1 μA
V
FBTRACK
V
FB
Voltage During Tracking V
TRACK
= 0.2V, V
ITH
= 1.2V (Note 4)
V
TRACK
= 0.4V, V
ITH
= 1.2V (Note 4)
180
380
200
400
220
420
mV
mV
ELECTRICAL CHARACTERISTICS
(Note 3) The denotes the specifi cations which apply over the full
operating temperature range, otherwise specifi cations are at T
A
= 25°C. V
CC
= V
DR
= V
BOOST
= V
SDB
= 5V, unless otherwise noted.