LTC3859 Linear Technology, LTC3859 Datasheet - Page 4

• Manufacturer Part Number: LTC3859
• Description: Buck/Buck/Boost Synchronous Controller
• Manufacturer: Linear Technology

ELECTRICAL CHARACTERISTICS
LTC3859
temperature range, otherwise specifi cations are at T
SYMBOL
UVLO
V
I
I
I
I
DF
DF
I
I
V
V
V
V
V
Gate Driver
TG1,2
BG1,2
TG3
BG3
TG1,2,3 t
TG1,2,3 t
BG1,2,3 t
BG1,2,3 t
TG/BG t
BG/TG t
t
t
INTV
V
V
4
SENSE1,2
SENSE3
SENSE1,2
SENSE3
TRACK/SS1,2
SS3
ON(MIN)1,2
ON(MIN)3
OVL1,2
RUN1
RUN2,3
RUN1,2,3
SENSE1,2,3(MAX)
SENSE3(CM)
INTVCCVBIAS
LDOVBIAS
MAX,TG
MAX,BG
CC
ON
+
–
1D
1D
Linear Regulator
ON
+
–
r
f
r
f
Hyst
PARAMETER
Undervoltage Lockout
Buck Feedback Overvoltage Protection
SENSE
SENSE
SENSE
SENSE
Maximum Duty Factor for TG
Maximum Duty Factor for BG
Soft-Start Charge Current
Soft-Start Charge Current
RUN1 Pin Threshold
RUN2,3 Pin Threshold
RUN Pin Hysteresis
Maximum Current Sense Threshold
SENSE3 Pins Common Mode Range
(BOOST Converter Input Supply Voltage)
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
TG Transition Time:
Rise Time
Fall Time
BG Transition Time:
Rise Time
Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
Buck Minimum On-Time
Boost Minimum On-Time
Internal V
INTV
CC
+
+
–
–
Load Regulation
Pin Current
Pin Current
Pin Current
Pin Current
CC
Voltage
J
≈ T
CONDITIONS
INTV
INTV
Measured at V
Regulated V
Bucks (Channels 1 and 2)
Boost (Channel 3)
Bucks (Channels 1 and 2)
V
V
Boost (Channel 3)
V
Bucks (Channels 1,2) in Dropout, FREQ = 0V
Boost (Channel 3) in Overvoltage
Bucks (Channels 1,2) in Overvoltage
Boost (Channel 3)
V
V
V
V
V
V
(Note 6)
C
C
(Note 6)
C
C
C
C
(Note 7)
(Note 7)
6V < V
I
CC
TRACK/SS1,2
OUT1,2
OUT1,2
SENSE3
SS3
RUN1
RUN2,3
FB1,2
FB1,2,3
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
A
= 0mA to 50mA, V
CC
CC
= 25°C. V
= 0V
The
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 3300pF Each Driver Bucks (Channels 1, 2)
= 3300pF Each Driver Bucks (Channels 1, 2)
BIAS
Rising
= 0.7V, V
Ramping Down
Ramping Up
+, V
< V
> V
= 1.1V, V
Rising
l
< 38V, V
INTVCC
INTVCC
SENSE3
FB1,2
= 0V
denotes the specifi cations which apply over the full operating junction
FB1,2
SENSE1,2
BIAS
SENSE3
– 0.5V
+ 0.5V
– = 12V
EXTVCC
Relative to
= 12V, V
EXTVCC
– = 3.3V
+ = 12V
= 0V, I
= 0V
RUN1,2,3
Boost (Channel 3)
Boost (Channel 3)
INTVCC
= 0mA
= 5V, EXTV
CC
l
l
l
l
l
= 0V unless otherwise noted.
1.19
1.23
MIN
3.5
0.7
0.7
2.5
5.0
98
43
7
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4.15
1.25
1.28
TYP
170
700
100
100
120
3.8
1.0
1.0
2.5
1.5
2.4
1.1
1.2
1.0
1.2
1.0
5.4
0.7
10
99
96
80
50
25
16
28
13
30
70
30
70
95
MAX
1.31
1.33
4.5
4.0
1.4
1.4
5.6
13
±1
±2
±1
57
38
2
UNITS
3859f
mV
mV
μA
μA
μA
μA
μA
μA
μA
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
%
%
%
%
%
%
Ω
Ω
Ω
Ω
Ω
Ω
Ω
Ω
V
V
V
V
V
V