LTC3615 Datasheet, PDF (3/32 Pages) Linear Technology – Dual 4MHz, 3A Synchronous Step-Down DC/DC Converter

LTC3615
Electrical Characteristics The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 2), SV_IN = PV_INx = 3.3V, R_T = 178k, R_SRLIM = 40.2k, unless
otherwise specified (Notes 1, 2, 11).
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX
V_IN
V_UVLO
Operating Voltage Range
Undervoltage Lockout Threshold
SV_IN Ramping Down
l 2.25
5.5
l 1.7
SV_IN Ramping Up
2.25
V_FB
I_FB
∆V_LINEREG
∆V_LOADREG
I_S
Feedback Voltage Internal Reference (Note 3) V_TRACK = SV_IN, V_SRLIM = 0V
0°C < T_J < 85°C
–40°C < T_J < 125°C
0.592 0.6 0.608
l 0.590
0.610
Feedback Voltage External Reference (Note 3) V_TRACK = 0.3V, V_SRLIM = SV_IN
(Note 7)
(Note 3) V_TRACK = 0.5V, V_SRLIM = SV_IN
0.289 0.3 0.311
0.489 0.5 0.511
Feedback Input Current
V_FBx = 0.6V
l
0
±30
Line Regulation
SV_IN = PV_INx = 2.25V to 5.5V (Note 4)
l
0.2
Load Regulation
V_ITHx from 0.5V to 0.9V (Note 4)
0.2
V_ITHx = SV_IN, V_FBx = 0.6V (Note 5)
2
Active Mode
V_FB1 = 0.5V, V_MODE = SV_IN, V_RUN2 = 0V (Note 6)
1100
V_FBx = 0.5V, V_MODE = SV_IN, V_RUNx = SV_IN (Note 6)
1900
Sleep Mode
Shutdown
V_FB1 = 0.7V, V_RUN1 = SV_IN, V_RUN2 = 0V,
V_MODE = 0V, V_ITH1 = SV_IN (Note 5)
V_FBx = 0.7V, V_RUN1 = SV_IN, V_RUN2 = 0V,
V_MODE = 0V (Note 4)
V_FBx = 0.7V, V_RUNx = SV_IN, V_MODE =0V,
V_ITHx = SV_IN (Note 5)
V_FBx = 0.7V, V_RUNx = SV_IN, V_MODE =0V,
I_TH = (Note 4)
SV_IN = PV_IN = 5.5V, V_RUNx = 0V
95
130
145 220
130 200
240 360
0.1
1
R_DS(ON)
I_LIM
Top Switch On-Resistance
Bottom Switch On-Resistance
Top Switch Current Limit
PV_INx = 3.3V (Note 10)
PV_INx = 3.3V (Note 10)
Sourcing (Note 8), V_FB = 0.5V
Duty Cycle <35%
Duty Cycle = 100%
75
55
4.5
6
7.5
3.6
Bottom Switch Current Limit
Sinking (Note 8), V_FB = 0.7V,
Forced Continuous Mode
–2.5 –3.5 –5
I_SW(LKG)
g_m(EA)
I_EAO
Switch Leakage Current
Error Amplifier Transconductance
Error Amplifier Output Current
SV_IN = PV_IN = 5.5V, V_RUNx = 0V
–5µA < I_TH < 5µA
(Note 4)
0.01
1
240
±30
t_SOFT-START
Internal Soft-Start Time
V_FBx from 0.06V to 0.54V, TRACK/SSx = SV_IN
0.65 1.1
1.7
R_{ON(TRACK/SS_DIS)} TRACK/SS Pull-Down Resistance at
200
Start-Up
t_{TRACK/SS_DIS}
f_OSC
Soft-Start Discharge Time at Start-Up
Internal Oscillator Frequency
R_RT/SYNC = 178k
V_RT/SYNC = SV_IN
70
l 1.85 2.25 2.65
l 1.8 2.25 2.7
f_SYNC
Synchronization Frequency
t_LOW, t_HIGH > 30ns
0.4
4
V_RT/SYNC
SYNC Level High
SYNC Level Low
1.2
0.3
UNITS
V
V
V
V
V
V
V
nA
%/V
%
%
µA
µA
µA
µA
µA
µA
µA
mΩ
mΩ
A
A
A
µA
µmho
µA
ms
Ω
µs
MHz
MHz
MHz
V
V
3615f