LTC3728 Datasheet, PDF (2/32 Pages) Linear Technology – Dual, 550kHz, 2-Phase Synchronous Step-Down Switching Regulator

LTC3728
ABSOLUTE AXI U RATI GS (Note 1)
Input Supply Voltage (V_IN).........................36V to – 0.3V
Top Side Driver Voltages
(BOOST1, BOOST2) ...................................42V to – 0.3V
Switch Voltage (SW1, SW2) .........................36V to – 5V
INTV_CC, EXTV_CC, RUN/SS1, RUN/SS2, (BOOST1-SW1),
(BOOST2-SW2), PGOOD .............................7V to – 0.3V
SENSE1⁺, SENSE2 ⁺, SENSE1^–,
SENSE2 ^– Voltages ........................ (1.1)INTV_CC to – 0.3V
PLLIN, PLLFLTR, FCB, Voltage ............ INTV_CC to – 0.3V
I_TH1, I_TH2, V_OSENSE1, V_OSENSE2 Voltages ... 2.7V to – 0.3V
Peak Output Current <10µs (TG1, TG2, BG1, BG2) ... 3A
INTV_CC Peak Output Current ................................ 50mA
Operating Temperature Range (Note 7) ... –40°C to 85°C
Junction Temperature (Note 2) ............................. 125°C
Storage Temperature Range ................. – 65°C to 125°C
Lead Temperature (Soldering, 10 sec)
(G Package Only) .................................................. 300°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
RUN/SS1 1
SENSE1⁺ 2
SENSE1^– 3
V_OSENSE1 4
PLLFLTR 5
PLLIN 6
FCB 7
I_TH1 8
SGND 9
3.3V_OUT 10
I_TH2 11
V_OSENSE2 12
SENSE2^– 13
SENSE2⁺ 14
28 PGOOD
27 TG1
26 SW1
25 BOOST1
24 V_IN
23 BG1
22 EXTV_CC
21 INTV_CC
20 PGND
19 BG2
18 BOOST2
17 SW2
16 TG2
15 RUN/SS2
G PACKAGE
28-LEAD PLASTIC SSOP
T_JMAX = 125°C, θ_JA = 95°C/W
ORDER PART
NUMBER
LTC3728EG
TOP VIEW
32 31 30 29 28 27 26 25
V_OSENSE1 1
PLLFLTR 2
PLLIN 3
24 BOOST1
23 V_IN
22 BG1
FCB 4
I_TH1 5
SGND 6
33
21 EXTV_CC
20 INTV_CC
19 PGND
3.3V_OUT 7
I_TH2 8
18 BG2
17 BOOST2
9 10 11 12 13 14 15 16
UH PACKAGE
32-LEAD (5mm × 5mm) PLASTIC QFN
T_JMAX = 125°C, θ_JA = 34°C/W
EXPOSED PAD IS SGND (MUST BE SOLDERED TO PCB)
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ORDER PART
NUMBER
LTC3728EUH
UH PART
MARKING
3728
ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V, V_{RUN/SS1, 2} = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Main Control Loops
V_{OSENSE1, 2} Regulated Feedback Voltage
(Note 3); I_{TH1, 2} Voltage = 1.2V
● 0.792 0.800 0.808
V
I_{VOSENSE1, 2} Feedback Current
(Note 3)
–5
– 50
nA
V_REFLNREG Reference Voltage Line Regulation V_IN = 3.6V to 30V (Note 3)
0.002 0.02
%/V
V_LOADREG Output Voltage Load Regulation
(Note 3)
Measured in Servo Loop; ∆I_TH Voltage = 1.2V to 0.7V ●
Measured in Servo Loop; ∆I_TH Voltage = 1.2V to 2.0V ●
0.1
0.5
%
– 0.1 – 0.5
%
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