LTC3839 Datasheet, PDF (4/50 Pages) Linear Technology – Fast, Accurate, 2-Phase, Single-Output Step-Down DC/DC Controller

LTC3839
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C. V_IN = 15V unless otherwise noted (Note 3).
SYMBOL
PARAMETER
Internal V_CC Regulator
V_DRVCC1
Internally Regulated DRV_CC1 Voltage
DRV_CC1 Load Regulation
V_EXTVCC
EXTV_CC Switchover Voltage
EXTV_CC Switchover Hysteresis
EXTV_CC to DRV_CC2 Voltage Drop
PGood Output
OV
PGOOD Overvoltage Threshold
UV
PGOOD Undervoltage Threshold
PGOOD Threshold Hysteresis
V_PGOOD(L)
t_D(PGOOD)
PGOOD Low Voltage
Delay from V_FB Fault (OV/UV) to PGOOD
Falling
Delay from V_FB Good to PGOOD Rising
CONDITIONS
6V < V_IN < 38V
I_DRVCC1 = 0mA to –100mA
EXTV_CC Rising
EXTV_CC Falling from Switchover Voltage
V_EXTVCC = 5V, I_DRVCC2 = –100mA
V_OUT Rising, with Respect to Regulated Voltage
V_OUT Falling, with Respect to Regulated Voltage
V_OUT Returning to Reference Voltage
I_PGOOD = 2mA
MIN TYP MAX UNITS
5.0 5.3
5.6
V
–1.5 –3.5
%
4.4 4.6
4.8
V
200
mV
200
mV
5
7.5
10
%
–5 –7.5 –10
%
2
%
0.1
0.3
V
50
μs
20
μs
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The junction temperature (T_J, in °C) is calculated from the ambient
temperature (T_A, in °C) and power dissipation (P_D, in Watts) according to
the formula:
T_J = T_A + (P_D • θ_JA)
where θ_JA (in °C/W) is the package thermal impedance.
Note 3: The LTC3839 is tested under pulsed loading conditions such that
T_J ≈ T_A. The LTC3839E is guaranteed to meet specifications over the 0°C
to 85°C operating junction temperature range. Specifications over the
–40°C to 125°C operating junction temperature range are assured by
design, characterization and correlation with statistical process controls.
The LTC3839I is guaranteed to meet specifications over the –40°C to
125°C operating junction temperature range . Note that the maximum
ambient temperature consistent with these specifications is determined by
specific operating conditions in conjunction with board layout, the rated
package thermal impedance and other environmental factors.
Note 4: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. The maximum
rated junction temperature will be exceeded when this protection is active.
Continuous operation above the specified absolute maximum operating
junction temperature may impair device reliability or permanently damage
the device.
Note 5: The LTC3839 is tested in a feedback loop that adjusts the
differential feedback voltage (V_OUTSENSE+ – V_{OUTSENSE–}) to
achieve specified error amplifier output voltages (ITH).
Note 6: Delay times are measured with top gate (TG) and bottom gate
(BG) driving minimum load, and using 50% levels.
Note 7: In order to simplify the total system error computation, the
regulated voltage is defined in one combined specification which includes
the effects of line, load and common mode variation. The combined
regulated voltage specification is tested by independently varying line,
load, and common mode, which by design do not significantly affect one
another. For any combination of line, load, and common mode variation,
the regulated voltage should be within the limits specified that are tested in
production to the following conditions:
• Line: V_IN = 4.5V to 38V, ITH = 1.2V, V_{OUTSENSE–} = 0V
• Load: V_IN = 15V, ITH = 0.5V to 1.9V, V_{OUTSENSE–} = 0V
• Common mode: V_IN = 15V, ITH = 1.2V, to V_{OUTSENSE–} = ±500mV
3839fa
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