RUN, DGEN ................................................ –0.3V to 76V
PLLIN/MODE, TMR, V
FB
, SPFB .................... –0.3V to 6V
INTV
CC
......................................................... –0.3V to 6V
EXTV
CC
...................................................... –0.3V to 14V
DRV
CC
, (BOOST1-SW1), (BOOST2-SW2) ....–0.3V to 11V
(SENSE1
+
-SENSE1
–
),
(SENSE2
+
-SENSE2
–
)............................. –0.3V to 0.3V
I
LIM
, SS, I
TH
, FREQ,
PHASMD, DTC ....................... –0.3V to INTV
CC
+ 0.3V
DRVUV, DRVSET........................–0.3V to INTV
CC
+ 0.3V
Operating Junction Temperature Range
(Notes 2, 3) ........................................ –40°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
PIN CONFIGURATION
TOP VIEW
SGEN
DGEN
PLLIN/MODE
FREQ
PHASMD
I
LIM
SENSE1
+
SENSE1
–
DTC
1
2
3
4
5
6
7
8
9
39
GND
38 TMR
37 SPFB
36 IS –
35 IS+
34 DG
33 CS
32 SG
31 V
IN
30 TG1
29 SW1
28 BOOST1
27 BG1
26 V
BIAS
25 EXTV
CC
24 DRV
CC
23 BG2
22 BOOST2
21 SW2
20 TG2
FREQ 1
PHASMD 2
I
LIM
3
SENSE1
+
SENSE1
–
PLLIN/MODE
TOP VIEW
DGEN
SGEN
SPFB
IS –
TMR
38 37 36 35 34 33 32
31 DG
30 CS
29 SG
28 V
IN
27 TG1
39
GND
26 SW1
25 BOOST1
24 BG1
23 V
BIAS
22 EXTV
CC
21 DRV
CC
20 BG2
13 14 15 16 17 18 19
SENSE2
+
V
FB
SS
CLKOUT
TG2
SW2
BOOST2
4
5
DRVUV 10
DRVSET 11
INTV
CC
12
RUN 13
I
TH
14
SENSE2
SENSE2
–
+
DTC 6
DRVUV 7
DRVSET 8
INTV
CC
9
RUN 10
I
TH
11
SENSE2
–
12
15
16
V
FB
17
SS 18
CLKOUT 19
FE PACKAGE
38-LEAD PLASTIC TSSOP
θ
JA
= 28°C/W
EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB
UHF PACKAGE
38-LEAD (5mm
×
7mm) PLASTIC QFN
θ
JA
= 34°C/W
EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB
IS+
2
Rev. A
For more information
www.analog.com
LTC3897
ORDER INFORMATION
LEAD FREE FINISH
LTC3897EUHF#PBF
LTC3897IUHF#PBF
LTC3897HUHF#PBF
LTC3897EFE#PBF
LTC3897IFE#PBF
LTC3897HFE#PBF
TAPE AND REEL
LTC3897EUHF#TRPBF
LTC3897IUHF#TRPBF
LTC3897HUHF#TRPBF
LTC3897EFE#TRPBF
LTC3897IFE#TRPBF
LTC3897HFE#TRPBF
PART MARKING*
3897
3897
3897
LTC3897FE
LTC3897FE
LTC3897FE
PACKAGE DESCRIPTION
38-Lead (5mm x 7mm) Plastic QFN
38-Lead (5mm x 7mm) Plastic QFN
38-Lead (5mm x 7mm) Plastic QFN
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
38-Lead Plastic TSSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
Contact the factory for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Tape and reel specifications.
Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix.
ELECTRICAL CHARACTERISTICS
SYMBOL
V
BIAS
PARAMETER
Bias Voltage Operating Range
SENSE Pins Common Mode Range
(BOOST Converter Input Supply Voltage)
V
IN
I
Q
Input Supply Voltage Operating Range
Reverse Input Current
Input DC Supply Current
Pulse-Skipping or Forced Continuous Mode
Burst Mode (Sleep)
Supply Voltage and Operating Current
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 12V, V
BIAS
= 12V, unless otherwise noted.
CONDITIONS
MIN
4.5
2.3
4.2
V
IN
= –30V
(Note 5)
RUN = 12V, V
FB
= 1.25V (No Load)
RUN = 12V, DGEN = SGEN = 0V, V
FB
= 1.25V
(No Load), CS = IS
+
= IS
–
= V
SPFB
= 0V
RUN = DGEN = 12V, SGEN = 0V, V
FB
= 1.25V
(No Load), CS = 12V, IS
+
= IS
–
= CS – 0.1V
RUN = 12V, DGEN = 0V, SGEN = 12V,
V
FB
= 1.25V (No Load), CS = IS
+
= IS
–
= 12V
RUN = DGEN = SGEN = 12V, V
FB
= 1.25V
(No Load), CS = 12V, IS
+
= IS
–
= CS – 0.1V
Shutdown
BOOST Controller Main Control Loop
V
OUT
V
FB
I
FB
Regulated Boost Output Voltage in
Synchronous Configuration
Regulated Feedback Voltage
Feedback Current
Reference Line Voltage Regulation
Output Voltage Load Regulation
I
TH
= 1.2 V (Note 4)
(Note 4)
(Note 4) V
IN
= 6V to 75V
(Note 4)
(Note 4) Measured in Servo Loop,
I
TH
Voltage = 1V to 0.6V
(Note 4) Measured in Servo Loop,
I
TH
Voltage = 1V to 1.4V
l
l
l
TYP
MAX
75
65
75
UNITS
V
V
V
µA
mA
0
1.32
55
125
260
325
15
–10
90
190
380
450
22
60
µA
µA
µA
µA
µA
V
V
nA
%/V
%
%
RUN = DGEN = SGEN = 0V
1.188
1.200
±10
0.002
0.01
–0.01
1.212
±50
0.02
0.1
–0.1
For more information
www.analog.com
3
Rev. A
LTC3897
ELECTRICAL CHARACTERISTICS
SYMBOL
g
m
UVLO
PARAMETER
Error Amplifier Transconductance
Undervoltage Lockout
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 12V, V
BIAS
= 12V, unless otherwise noted.
CONDITIONS
I
TH
= 1.2 V
DRV
CC
Ramping Up
DRVUV = 0V
DRVUV = INTV
CC
l
l
l
l
l
MIN
TYP
2
4.0
7.5
MAX
UNITS
mmho
4.2
7.8
4.0
7.0
1.38
13
155
105
55
12
10
9
350
±2
V
V
V
V
V
mV
µA
mV
mV
mV
mV
mV
mV
µA
µA
Ω
Ω
Ω
Ω
Ω
DRV
CC
Ramping Down
DRVUV = 0V
DRVUV = INTV
CC
V
RUN
I
SS
RUN Pin ON Threshold
RUN Pin Hysteresis
Soft-Start Charge Current
V
SS
= GND
V
FB
= 1.15V, I
LIM
= INTV
CC
, V
SENSE
+ = 12V
V
FB
= 1.15V, I
LIM
= Float, V
SENSE
+ = 12V
V
FB
= 1.15V, I
LIM
= GND, V
SENSE
+ = 12V
Matching Between V
SENSE1(MAX)
and
V
SENSE2(MAX)
SENSE
+
Pin Current
SENSE
–
Pin Current
Top Gate Pull-Up Resistance
Top Gate Pull-Down Resistance
Bottom Gate Pull-Up Resistance
Bottom Gate Pull-Down Resistance
BDSW
BOOST to DRV
CC
Switch On-Resistance
Top Gate Off to Bottom Gate On Switch-On
Delay Time
V
FB
= 1.15V, I
LIM
= INTV
CC
, V
SENSE
+ = 12V
V
FB
= 1.15V, I
LIM
= Float, V
SENSE
+ = 12V
V
FB
= 1.15V, I
LIM
= GND, V
SENSE
+ = 12V
V
FB
= 1.1V, I
LIM
= Float
V
FB
= 1.1V, I
LIM
= Float
DRV
CC
= 10V
DRV
CC
= 10V
DRV
CC
= 10V
DRV
CC
= 10V
V
SW
= 0V, V
DRVSET
= INTV
CC
DTC = 0V
DTC = Float
DTC = INTV
CC
Bottom Gate Off to Top Gate On Switch-On
Delay Time
DTC = 0V
DTC = Float
DTC = INTV
CC
Maximum BG Duty Factor
t
ON(MIN)
Minimum BG On-Time
DRV
CC
Voltage from Internal V
BIAS
LDO
DRV
CC
Load Regulation from V
BIAS
LDO
DRV
CC
Voltage from Internal EXTV
CC
LDO
DRV
CC
Load Regulation from
Internal EXTV
CC
LDO
(Note 7) V
DRVSET
= INTV
CC
V
EXTVCC
= 0V
7V < V
BIAS
< 75V, DRVSET = 0V
11V < V
BIAS
< 75V, DRVSET = INTV
CC
I
CC
= 0mA to 50mA, V
EXTVCC
= 0V,
V
DRVSET
= INTV
CC
7V < V
EXTVCC
< 13V, DRVSET = 0V
11V < V
EXTVCC
< 13V, DRVSET = INTV
CC
I
CC
= 0mA to 50mA, V
EXTVCC
= 8.5V,
V
DRVSET
= 0V
DRV
CC
LDO Regulator
V
RUN
Rising
3.6
6.4
1.18
7
3.8
6.7
1.28
100
10
140
95
48
0
0
0
250
2.5
1.5
2.5
1
V
SENSE1,2(MAX)
Maximum Current Sense Threshold
l
l
l
l
l
l
125
85
41
–12
–10
–9
2.6
3.7
55
90
170
55
90
170
96
90
75
130
275
75
130
275
ns
ns
ns
ns
ns
ns
%
ns
5.8
9.6
6.0
10.0
0.7
6.2
10.4
2
6.2
10.4
2
V
V
%
V
V
%
5.8
9.6
6.0
10.0
0.7
4
Rev. A
For more information
www.analog.com
LTC3897
ELECTRICAL CHARACTERISTICS
SYMBOL
PARAMETER
EXTV
CC
LDO Switchover Voltage
EXTV
CC
Hysteresis
Programmable DRV
CC
Programmable DRV
CC
Programmable DRV
CC
Oscillator and Phase-Locked Loop
Programmable Frequency
R
FREQ
= 25k
R
FREQ
= 60k
R
FREQ
= 100k
Lowest Fixed Frequency
Highest Fixed Frequency
f
SYNC
Synchronizable Frequency
PLLIN/MODE Input High Level
PLLIN/MODE Input Low Level
BOOST1 and BOOST2 Charge Pump
BOOST Charge Pump Available Output
Current
FREQ = 0V, Forced Continuous or
Pulse-Skipping Mode
V
SW1,2
= 12V; V
BOOST1,2
= 16.5V
V
SW1,2
= 12V; V
BOOST1,2
= 19.5V
V
SGEN
Rising
V
IN
= 4.2V, I
SG
= 0, –1µA, DG – CS = 1V
V
IN
= 8V to 70V, I
SG
= 0, −1µA
SG Pin Pull-Up Current
SG Pin Pull-Down Current
V
IN
= SG = DG = CS = 12V
Overvoltage: SPFB = 1.5V, SG – CS = 5V
Overcurrent: ΔV
IS
= 100mV, SG – CS = 5V
Shutdown: DGEN = SGEN = 0V, SG – CS = 5V
CS Pin Input Current
V
IN
= CS = 12V, IS
+
= IS
–
= 11.9V, SGEN = Float
V
IN
= CS = 12V, SGEN = 0V
V
CS
= –30V
V
SPFB
ΔV
IS
Regulated Surge Protection Feedback Voltage
Overcurrent Fault Threshold, (V
IS+
– V
IS
–)
IS
+
Pin Input Current
SPFB Pin Input Current
IS
–
Pin Input Current
IS
–
> 2.5V
IS
–
= 1.5V
IS
+
= IS
–
= V
IN
= CS = 12V, SGEN = DGEN = Float
IS
+
= IS
–
= V
IN
= CS = 12V, SGEN = DGEN = 0V
SPFB = 1.235V
IS
+
= IS
–
= V
IN
= CS = 12V, SGEN = DGEN = Float
IS
+
= IS
–
= V
IN
= CS = 12V, SGEN = DGEN = 0V
l
The
l
denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T