LTC3445 Datasheet, PDF (2/24 Pages) Linear Technology – I2C Controllable Buck Regulator with Two LDOs in a 4mm × 4mm QFN

LTC3445
ABSOLUTE AXI U RATI GS
(Note 1)
V_CC1, V_CC2, SDA, SCL Voltages .................. – 0.3V to 6V
RUN, V_TRACK, V_BACKUP, PGOOD, ADD7,
ADD6, FB, V_CC BATT,
BATTFAULT Voltages .............................. – 0.3V to V_CC1
SW Voltage ................................ – 0.3V to (V_CC1 + 0.3V)
LDO1FB, LDO2FB Voltages ..................... – 0.3V to V_CC2
LDO1, LDO2 Voltages ................ – 0.3V to (V_CC2 + 0.3V)
LDO1, LDO2 Source Current ............................... 50mA
V_CC BATT Source Current ...................................... 8mA
P-Channel Switch Source Current (DC) ............. 800mA
N-Channel Switch Sink Current (DC) ................. 800mA
Peak SW Sink and Source Current ........................ 1.3A
LDO1, LDO2, V_CC BATT Output Short-Circuit
Duration .......................................................... Indefinite
Operating Temperature Range (Note 2) ...–40°C to 85°C
Junction Temperature (Note 3) ............................ 125°C
Storage Temperature Range ................. –65°C to 125°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
24 23 22 21 20 19
V_TRACK 1
V_BACKUP 2
V_CC1 3
PGOOD 4
ADD7 5
SDA 6
18 V_CC BATT
17 FB
16 NC
25
15 RUN
14 SW
13 NC
7 8 9 10 11 12
UF PACKAGE
24-LEAD (4mm × 4mm) PLASTIC QFN
T_JMAX = 125°C, θ_JA = 37°C/W, θ_JC = 2.6°C/W
EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB
ORDER PART NUMBER UF PART MARKING
LTC3445EUF
3445
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.
ELECTRICAL CHARACTERISTICS _{The ● denotes the specifications which apply over the full operating}
temperature range, otherwise specifications are at T_A = 25°C. V_CC1 = V_CC2 = 3.6V, unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX
V_CC1, V_CC2 Input Voltage Range
RUN
Run Threshold
● 2.5
5.5
● 0.3
1
1.5
PGOOD Reports Undervoltage of any Regulator
PGOOD = 0.4V
●
3
I_S
DC Bias Current (Shutdown)
RUN = 0
DC Bias Current (Buck, LDO1, LDO2 Disabled) RUN = V_CC1
27
50
105 150
Buck Regulator
R_FB
Feedback Resistance
340
V_OUT(MIN) Regulated Output Voltage
I_OUT = 100mA, Burst Mode Operation
Disabled
● 0.824 0.850 0.875
V_OUT(MAX) Regulated Output Voltage
I_OUT = 100mA, Burst Mode Operation
Disabled
● 1.504 1.55 1.597
V_OUT(STEP) Output Voltage Step Size (0 to 48)
Output Voltage Slew Rate = 00
I_OUT = 100mA
I_OUT = 100mA, V_OUT = 0.85V to 1.55V
● 13.1 14.7 16.1
11.3
Output Voltage Slew Rate = 01
I_OUT = 100mA, V_OUT = 0.85V to 1.55V
7.5
Output Voltage Slew Rate = 10
I_OUT = 100mA, V_OUT = 0.85V to 1.55V
3.8
Output Voltage Slew Rate = 11
I_PK
Peak Inductor Current
I_OUT = 100mA, V_OUT = 0.85V to 1.55V
V_CC1 = 3V, V_FB = 0.5V or V_OUT = 90%,
Duty Cycle < 35%
0.9
0.75
1
1.25
V_LOADREG Output Voltage Load Regulation
0.5
UNITS
V
V
mA
µA
µA
kΩ
V
V
mV
mV/µs
mV/µs
mV/µs
mV/µs
A
%
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