LTC1625 Datasheet, PDF (3/24 Pages) Linear Technology – No RSENSE TM Current Mode Synchronous Step-Down Switching Regulator

LTC1625
ELECTRICAL CHARACTERISTICS T_A = 25°C, V_IN = 15V unless otherwise noted.
SYMBOL
PARAMETER
BG t_R
BG t_F
BG Transition Time
Rise Time
Fall Time
Internal V_CC Regulator
V_INTVCC
Internal V_CC Voltage
V_LDOINT
INTV_CC Load Regulation
V_LDOEXT
EXTV_CC Voltage Drop
V_EXTVCC
EXTV_CC Switchover Voltage
Oscillator
f_OSC
f_H/f_OSC
V_SYNC
R_SYNC
Oscillator Freqency
Maximum Synchronized Frequency Ratio
SYNC Pin Threshold (Figure 4)
SYNC Pin Input Resistance
CONDITIONS
C_LOAD = 3300pF
C_LOAD = 3300pF
6V < V_IN < 30V, V_EXTVCC = 4V
I_CC = 20mA, V_EXTVCC = 4V
I_CC = 20mA, V_EXTVCC = 5V
I_CC = 20mA, V_EXTVCC Ramping Positive
Ramping Positive
MIN
q 5.0
q 4.5
135
TYP MAX
50
150
50
150
5.2
5.4
–1
–2
180
300
4.7
150
165
1.5
0.9
1.2
50
UNITS
ns
ns
V
%
mV
V
kHz
V
kΩ
The q denotes specifications which apply over the full operating
temperature range.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: T_J is calculated from the ambient temperature T_A and power
dissipation P_D according to the following formula:
LTC1625CGN/LTC1625IGN: T_J = T_A + (P_D • 130°C/W)
LTC1625CS/LTC1625IS: T_J = T_A + (P_D • 110°C/W)
Note 3: The LTC1625 is tested in a feedback loop that adjusts V_OSENSE to
achieve a specified error amplifier output voltage (I_TH).
Note 4: Typical in application circuit with EXTV_CC tied to V_OUT = 5V,
I_OUT = 0A and FCB = INTV_CC. Dynamic supply current is higher due
to the gate charge being delivered at the switching frequency. See
Applications Information.
Note 5: Minimum input supply voltage is 3.9V at – 40°C for industrial
grade parts.
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