LTC1736 Datasheet, PDF (2/28 Pages) Linear Technology – 5-Bit Adjustable High Efficiency Synchronous Step-Down Switching Regulator

LTC1736
ABSOLUTE AXI U RATI GS
(Note 1)
Input Supply Voltage (V_IN).........................36V to – 0.3V
Topside Driver Supply Voltage (BOOST)....42V to – 0.3V
Switch Voltage (SW) ....................................36V to – 5V
EXTV_CC, VIDV_CC, (BOOST – SW) Voltages ..7V to – 0.3V
SENSE⁺, SENSE^–.......................... 1.1(INTV_CC) to – 0.3V
FCB Voltage ............................(INTV_CC + 0.3V) to – 0.3V
I_TH, V_OSENSE, V_FB Voltage .........................2.7V to – 0.3V
RUN/SS, VID0 to VID4, PGOOD Voltages ....7V to – 0.3V
Peak Driver Output Current <10µs (TG, BG) .............. 3A
INTV_CC Output Current ......................................... 50mA
Operating Ambient Temperature Range
LTC1736C ............................................... 0°C to 85°C
LTC1736I ............................................ – 40°C to 85°C
Junction Temperature (Note 2) ............................. 125°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
C_OSC 1
RUN/SS 2
I_TH 3
FCB 4
SGND 5
PGOOD 6
SENSE ^– 7
SENSE ⁺ 8
V_FB 9
V_OSENSE 10
VID0 11
VID1 12
24 TG
23 BOOST
22 SW
21 V_IN
20 INTV_CC
19 BG
18 PGND
17 EXTV_CC
16 VIDV_CC
15 VID4
14 VID3
13 VID2
G PACKAGE
24-LEAD PLASTIC SSOP
T_JMAX = 125°C, θ_JA = 110°C/W
Consult factory for Military grade parts.
ORDER PART
NUMBER
LTC1736CG
LTC1736IG
ELECTRICAL CHARACTERISTICS The q denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V, V_RUN/SS = 5V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX
Main Control Loop
V_OSENSE
∆V_LINEREG
∆V_LOADREG
Output Voltage Set Accuracy
Reference Voltage Line Regulation
Output Voltage Load Regulation
g_m
V_FCB
I_FCB
V_OVL
I_Q
V_RUN/SS
V_RUN/SS
I_RUN/SS
I_SCL
Transconductance Amplifier g_m
Forced Continuous Threshold
Forced Continuous Current
Feedback Overvoltage Lockout
Input DC Supply Current
Normal Mode
Shutdown
Run Pin Start Threshold
Run Pin Begin Latchoff Threshold
Soft-Start Charge Current
RUN/SS Discharge Current
UVLO
∆V_SENSE(MAX)
I_SENSE
t_ON(MIN)
TG t_r
TG t_f
Undervoltage Lockout
Maximum Current Sense Threshold
SENSE Pins Total Source Current
Minimum On-Time
TG Transition Time:
Rise Time
Fall Time
(Note 3) See Table 1
V_IN = 3.6V to 30V (Note 3)
(Note 3)
Measured in Servo Loop; V_ITH = 0.7V
Measured in Servo Loop; V_ITH = 2V
V_FCB = 0.85V
(Note 4)
V_RUN/SS = 0V
V_RUN/SS, Ramping Positive
V_RUN/SS, Ramping Positive
V_RUN/SS = 0V
Soft Short Condition, V_FB = 0.5V,
V_RUN/SS = 4.5V
Measured at V_IN Pin (V_IN Ramping Down)
V_FB = 0.7V
V_SENSE– = V_SENSE+ = 0.8V
Tested with a Square Wave (Note 8)
(Note 9)
C_LOAD = 3300pF
C_LOAD = 3300pF
q
1
0.001 0.02
q
0.1
0.3
q
– 0.1 – 0.3
1.3
q 0.76
0.8
0.84
– 0.17 – 0.3
q 0.84 0.86 0.88
450
15
25
1.0
1.5
1.9
4.1
4.5
– 0.7 – 1.2
0.5
2
4
q
q 60
3.5
3.9
75
85
60
80
160 200
50
90
50
90
UNITS
%
%/V
%
%
mmho
V
µA
V
µA
µA
V
V
µA
µA
V
mV
µA
ns
ns
ns
2