LTC3855_15 Datasheet, PDF (3/44 Pages) Linear Technology – Dual, Multiphase Synchronous DC/DC Controller with Differential Remote Sense

LTC3855
Order information
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC3855EFE#PBF
LTC3855EFE#TRPBF
LTC3855FE
38-Lead Plastic TSSOP
–40°C to 85°C
LTC3855IFE#PBF
LTC3855IFE#TRPBF
LTC3855FE
38-Lead Plastic TSSOP
–40°C to 125°C
LTC3855EUJ#PBF
LTC3855EUJ#TRPBF
LTC3855UJ
40-Lead (6mm × 6mm) Plastic QFN –40°C to 85°C
LTC3855IUJ#PBF
LTC3855IUJ#TRPBF
LTC3855UJ
40-Lead (6mm × 6mm) Plastic QFN –40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
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/
Electrical Characteristics The l denotes the specifications which apply over the full operating
junction temperature range (E-Grade), otherwise specifications are at T_A = 25°C. V_IN = 15V, V_RUN1,2 = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP MAX UNITS
Main Control Loops
V_IN
V_OUT
V_FB1,2
Input Voltage Range
Output Voltage Range
Regulated Feedback Voltage
I_FB1,2
V_REFLNREG
V_LOADREG
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
g_m1,2
I_Q
Transconductance Amplifier g_m
Input DC Supply Current
Normal Mode
Shutdown
DF_MAX
UVLO
Maximum Duty Factor
Undervoltage Lockout
UVLO_HYS UVLO Hysteresis
V_OVL1,2
Feedback Overvoltage Lockout
I_SENSE1,2 Sense Pins Bias Current
I_TEMP1,2
DCR Tempco Compensation Current
I_TK/SS1,2 Soft-Start Charge Current
V_RUN1,2
RUN Pin ON Threshold
V_RUN1,2HYS RUN Pin ON Hysteresis
V_SENSE(MAX) Maximum Current Sense Threshold
TG1, 2 t_r
TG1, 2 t_f
BG1, 2 t_r
BG1, 2 t_f
TG Transition Time:
Rise Time
Fall Time
BG Transition Time:
Rise Time
Fall Time
I_TH1,2 Voltage = 1.2V (Note 4)
l
I_TH1,2 Voltage = 1.2V (Note 4), T_A = 125°C
l
(Note 4)
V_IN = 4.5V to 38V (Note 4)
(Note 4)
Measured in Servo Loop; ∆I_TH Voltage = 1.2V to 0.7V l
Measured in Servo Loop; ∆I_TH Voltage = 1.2V to 1.6V l
I_TH1,2 = 1.2V; Sink/Source 5µA; (Note 4)
(Note 5)
V_IN = 15V
V_RUN1,2 = 0V
In Dropout, f_OSC = 500kHz
V_INTVCC Ramping Down
l
Measured at V_FB1,2
l
(Each Channel); V_SENSE1,2 = 3.3V
l
V_ITEMP1,2 = 0.2V
l
V_TK/SS1,2 = 0V
l
V_RUN1, V_RUN2 Rising
l
V_FB1,2 = 0.5V, V_SENSE1,2 = 3.3V, I_LIM = 0V
l
V_FB1,2 = 0.5V, V_SENSE1,2 = 3.3V, I_LIM = Float
l
V_FB1,2 = 0.5V, V_SENSE1,2 = 3.3V, I_LIM = INTV_CC
l
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
4.5
0.6
0.5955
0.594
94
3.0
0.64
9
1
1.1
25
45
68
0.600
0.600
–15
0.002
38
V
12.5
V
0.6045
V
0.606
V
–50
nA
0.02 %/V
0.01
–0.01
2
0.1
%
–0.1
%
mmho
3.5
mA
30
50
µA
95
%
3.2
3.4
V
0.6
V
0.66 0.68
V
±1
±2
µA
10
11
µA
1.2
1.4
µA
1.22 1.35
V
80
mV
30
35
mV
50
55
mV
75
82
mV
25
ns
25
ns
25
ns
25
ns
3855f