LTC7878

3

Rev. 0

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ELECTRICAL CHARACTERISTICS The

l

denotes the specifications which apply over the specified operating

junction temperature range, otherwise specifications are at TA = 25°C. , VIN = 12V, RUN > 1.25V unless otherwise noted. (Note 2)

SYMBOL

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Bias Supply (VIN, EXTVCC)

VIN

Bias Input Supply Operating Voltage Range

5

70

V

EXTVcc

Auxiliary Bias Voltage Operating Range

5

70

V

IQ

VIN Supply Current (Shutdown Mode)

VIN = 5V, RUN = 0V, EXTVCC = 0V

70

100

µA

VIN Supply Current (Standby Mode)

VIN = 5V, RUN = 0.9V, EXTVCC = 0V

3

mA

Controller Operation

VOUT

Output Voltage Operating Range

1

70

V

VFB

Regulated Feedback Voltage

(Note 4) ITH, ITHB Voltage = 1.2V

l

0.99

1.00

1.01

V

IVFB

VFB Pin Current

(Note 4)

–50

–100

nA

VREFLNREG

Reference Voltage Line Regulation

(Note 4), VIN = 12V to 72V

0.01

0.2

%

VLOADREG

Output Voltage Load Regulation

Measure in Servo Loop, ITH = ITHB,

∆ITH Voltage = 1.2V to 1.8V

0.05

0.2

%

Measure in Servo Loop, ITH = ITHB,

∆ITH Voltage = 1.2V to 0.6V

–0.05

–0.2

%

gm

Error Amplifier Transconductance gm

(Note 4) ITH = ITHB = 1.2V, Sink/Source = 10μA

2

mmho

gmb (Buck)

Error Amplifier Transconductance gmb

(Note 4) ITH = ITHB = 1.2V, Sink/Source = 10μA

1

mmho

UVLO_DRVCC

DRVCC Undervoltage Lockout

DRVCC Ramping Down

3.9

4.3

4.5

V

UVLO_DRV_HYS DRVCC Undervoltage Hysteresis

0.35

V

UVLO_INTVCC

INTVCC Undervoltage Lockout

INTVCC Ramping Down

3.95

V

UVLO_INTV_HYS INTVCC Undervoltage Hysteresis

0.45

V

VRUN

RUN Pin Threshold 1 (Shutdown to Standby)

RUN Pin Threshold 2 (Standby to On)

VRUN Rising

VRUN Rising

0.3

1.1

0.57

1.2

1.3

V

V

IRUN

RUN Pin Source Current

VRUN <0.57V

0.57V < VRUN < 1.2V

VRUN > 1.2V

1

2

6

µA

µA

µA

ISS

Soft-Start (SS Pin) Source Current

2.5

µA

DMAX_BG2

Maximum Duty Cycle of Boost Mode (BG2)

90

%

Inductor Current Sensing

VSENSE(ILMAX)

Maximum Inductor Peak Current Sense

Threshold

MODE/ILIM < INTVCC/2, ITH = ITHB = 2.1V,

VISNSP– VISNSD = 25mV

l

18

25

32

mV

MODE/ILIM > INTVCC/2, ITH = ITHB = 2.1V,

VISNSP – VISNSD = 50mV

l

40

50

60

mV

MODE/ILIM < INTVCC/2, ITH = ITHB = 2.1V,

VISNSP = VISNSD

l

92

100

108

mV

MODE/ILIM > INTVCC/2, ITH = ITHB = 2.1V,

VISNSP = VISNSD

l

190

200

210

mV

IISNSD

ISNSD Pin Leakage Current

0

±0.1

µA

IISNSN

ISNSN Pin Leakage Current

0

±0.1

µA

Input/Output Average Current Regulation

ICSP

CSP Pin Input Current

VCSP = VCSN > 5V, VCSP – VCSN = 50mV

14

20

µA

ICSN

CSN Pin Input Current

VCSP = VCSN > 5V, VCSP – VCSN = 50mV

14

20

µA

∆ICS

CSP/CSN Pin Current Mismatch

VCSP = 12V, VCSP – VCSN = 50mV

0.05

±1

µA

VMAX(IAVG)

Maximum Average Current Limit

VCSP = 12V

l

46.5

50

53

mV

ISETCUR

SETCUR Pin Output Current

14

15

16

µA