RUN1, RUN2, RUN3 .................................... –0.3V to 8V
Maximum Current Sourced Into Pin
from Source >8V ..............................................100µA
SENSE1
+
, SENSE2
+
, SENSE1
–
SENSE2
–
Voltages ................................. –0.3V to 28V
SENSE3
+
, SENSE3
–
Voltages ..................... –0.3V to 40V
FREQ Voltages ......................................–0.3V to INTV
CC
EXTV
CC
...................................................... –0.3V to 14V
I
TH1
, I
TH2
, I
TH3
, V
FB1
, V
FB2
, V
FB3
Voltages.... –0.3V to 6V
PLLIN/MODE, PGOOD1, OV3 Voltages ........ –0.3V to 6V
TRACK/SS1, TRACK/SS2, SS3 Voltages ..... –0.3V to 6V
Operating Junction Temperature Range (Notes 2, 3)
LTC7815E, LTC7815I .......................... –40°C to 125°C
LTC7815H .......................................... –40°C to 150°C
Storage Temperature Range .............. –65°C to 150°C
PIN CONFIGURATION
TOP VIEW
TRACK/SS1
SENSE1
–
SENSE1
+
PGOOD1
V
FB1
I
TH1
38 37 36 35 34 33 32
FREQ 1
PLLIN/MODE 2
SS3 3
SENSE3
+
TG1
31 SW1
30 BOOST1
29 BG1
28 SW3
27 TG3
26 BOOST3
25 BG3
24 V
BIAS
23 EXTV
CC
22 INTV
CC
21 BG2
20 BOOST2
SW2
4
5
39
PGND
SENSE3
–
V
FB3
6
I
TH3
7
SGND 8
RUN1 9
RUN2 10
RUN3 11
SENSE2 12
–
13 14 15 16 17 18 19
V
FB2
I
TH2
TRACK/SS2
OV3
SENSE2
+
TG2
UHF PACKAGE
38-LEAD (5mm
×
7mm) PLASTIC QFN
T
JMAX
= 150°C,
q
JA
= 34.7°C/W,
q
JC
= 2°C/W
EXPOSED PAD (PIN 39) IS PGND, MUST BE SOLDERED TO PCB
7815f
2
For more information
www.linear.com/LTC7815
LTC7815
ORDER INFORMATION
LEAD FREE FINISH
LTC7815EUHF#PBF
LTC7815IUHF#PBF
LTC7815HUHF#PBF
TAPE AND REEL
LTC7815EUHF#TRPBF
LTC7815IUHF#TRPBF
LTC7815HUHF#TRPBF
http://www.linear.com/product/LTC7815#orderinfo
PART MARKING*
7815
7815
7815
PACKAGE DESCRIPTION
38-Lead (5mm × 7mm) Plastic QFN
38-Lead (5mm × 7mm) Plastic QFN
38-Lead (5mm × 7mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
Consult ADI Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Notes 2, 4). V
BIAS
= 12V, V
RUN1,2,3
= 5V, EXTV
CC
= 0V unless
otherwise noted.
SYMBOL
V
BIAS
V
FB1,2
PARAMETER
Bias Input Supply Operating Voltage
Range
Buck Regulated Feedback Voltage
(Note 4); I
TH1,2
Voltage = 1.2V
0°C to 85°C, All Grades
LTC7815E, LTC7815I
LTC7815H
(Note 4); I
TH3
Voltage = 1.2V
0°C to 85°C, All Grades
LTC7815E, LTC7815I
LTC7815H
(Note 4)
(Note 4); V
IN
= 4.5V to 38V
(Note 4)
Measured in Servo Loop;
∆I
TH
Voltage = 1.2V to 0.7V
Measured in Servo Loop;
∆I
TH
Voltage = 1.2V to 2V
g
m1,2,3
Transconductance Amplifier g
m
(Note 4); I
TH1,2,3
= 1.2V;
Sink/Source 5µA
l
l
ELECTRICAL CHARACTERISTICS
CONDITIONS
MIN
4.5
TYP
MAX
38
UNITS
V
l
l
0.792
0.788
0.786
1.183
1.181
1.176
0.800
0.800
0.800
1.200
1.200
1.200
–2
0.002
0.01
–0.01
2
0.808
0.812
0.812
1.214
1.218
1.218
±50
0.02
0.1
–0.1
V
V
V
V
V
V
nA
%/V
%
%
mmho
V
FB3
Boost Regulated Feedback Voltage
l
l
I
FB1,2,3
V
REFLNREG
V
LOADREG
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
7815f
For more information
www.linear.com/LTC7815
3
LTC7815
ELECTRICAL CHARACTERISTICS
SYMBOL
I
Q
PARAMETER
Input DC Supply Current
Pulse-Skipping or
Forced Continuous Mode
(One Channel On)
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Notes 2, 4). V
BIAS
= 12V, V
RUN1,2,3
= 5V, EXTV
CC
= 0V unless
otherwise noted.
CONDITIONS
(Note 5)
RUN1 = 5V and RUN2,3 = 0V or
RUN2 = 5V and RUN1,3 = 0V or
RUN3 = 5V and RUN1,2 = 0V
V
FB1, 2
ON = 0.83V (No Load)
V
FB3
= 1.25V
RUN1,2,3 = 5V,
V
FB1,2
= 0.83V (No Load)
V
FB3
= 1.25V
RUN1 = 5V and RUN2,3 = 0V or
RUN2 = 5V and RUN1,3 = 0V
V
FB,ON
= 0.83V (No Load)
RUN3 = 5V and RUN1,2 = 0V
V
FB3
= 1.25V
RUN1 = 5V and RUN2 = 0V or
RUN2 = 5V and RUN1 = 0V
RUN3 = 5V
V
FB1,2
= 0.83V (No Load)
V
FB3
= 1.25V
RUN1,2,3 = 5V,
V
FB1,2
= 0.83V (No Load)
V
FB3
= 1.25V
RUN1,2,3 = 0V
INTV
CC
Ramping Up
INTV
CC
Ramping Down
V
OVL1,2
I
SENSE1,2
+
I
SENSE3
+
I
SENSE1,2
–
I
SENSE3
–
DF
MAX,TG
DF
MAX,BG
I
TRACK/SS1,2
I
SS3
V
RUN1
ON
V
RUN2,3
ON
V
RUN1,2,3
Hyst
Buck Feedback Overvoltage Protection
SENSE
+
Pin Current
SENSE
+
Pin Current
SENSE
–
Pin Current
SENSE
–
Pin Current
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
V
FB1,2
= 0.7V, V
SENSE1,2
– = 3.3V
V
FB1,2,3
= 1.1V, V
SENSE3
+ = 12V
l
l
l
l
l
MIN
TYP
1.5
MAX
UNITS
mA
Pulse-Skipping or
Forced Continuous Mode
(All Channels On)
Sleep Mode
(One Channel On, Buck)
Sleep Mode
(One Channel On, Boost)
Sleep Mode
(Buck and Boost Channel On)
3
mA
28
35
33
33
40
48
59
53
46
59
µA
µA
µA
Sleep Mode
(All Three Channels On)
Shutdown
UVLO
Undervoltage Lockout
38
56
µA
10
4.15
3.5
7
3.8
10
20
4.5
4.0
13
±1
µA
V
V
%
µA
µA
Measured at V
FB1,2
Relative to
Regulated V
FB1,2
Bucks (Channels 1 and 2) V
OUT
= 3.3V
Boost (Channel 3)
Bucks (Channels 1 and 2)
V
OUT
= 3.3V
V
OUT1,2
> V
INTVCC
+ 0.5V
Boost (Channel 3)
V
SENSE3
+, V
SENSE3
– = 12V
Bucks (Channels 1,2) in Dropout, FREQ = 0V
Boost (Channel 3) in Overvoltage
Bucks (Channels 1,2) in Overvoltage
Boost (Channel 3)
V
TRACK/SS1,2
= 0V
V
SS3
= 0V
V
RUN1
Rising
V
RUN2,3
Rising
l
l
170
±2
±1
97
98
100
100
90
3
3
1.18
1.21
43
2.5
5
5
1.24
1.27
70
50
57
38
8
8
1.32
1.33
700
µA
µA
µA
%
%
%
%
µA
µA
V
V
mV
mV
V
V
SENSE1,2,3(MAX)
Maximum Current Sense Threshold
V
SENSE3(CM)
SENSE3 Pins Common Mode Range
(BOOST Converter Input Supply Voltage)
7815f
4
For more information
www.linear.com/LTC7815
LTC7815
ELECTRICAL CHARACTERISTICS
SYMBOL
Gate Driver
TG1,2
BG1,2
TG3
BG3
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
CC
Voltage
INTV
CC
Load Regulation
Internal V
CC
Voltage
INTV
CC
Load Regulation
EXTV
CC
Switchover Voltage
EXTV
CC
Hysteresis
Programmable Frequency
Programmable Frequency
Programmable Frequency
Low Fixed Frequency
High Fixed Frequency
Synchronizable Frequency
PLLIN/MODE Input High Level
PLLIN/MODE Input Low Level
R
FREQ
= 25k; PLLIN/MODE = DC Voltage
R
FREQ
= 65k; PLLIN/MODE = DC Voltage
R
FREQ
= 100k; PLLIN/MODE = DC Voltage
V
FREQ
= 0V PLLIN/MODE = DC Voltage
V
FREQ
= INTV
CC
; PLLIN/MODE = DC Voltage
PLLIN/MODE = External Clock
PLLIN/MODE = External Clock
PLLIN/MODE = External Clock
l
l
l
l
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T