LTC3819 Datasheet, PDF (3/32 Pages) Linear Technology – 2-Phase, High Efficiency, Step-Down Controller for Sun Server CPUs

LTC3819
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_BIAS = 5V, V_RUN/SS = 5V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX UNITS
g_m
g_mOL
I_Q
I_RUN/SS
V_RUN/SS
V_RUN/SSLO
I_SCL
I_SDLHO
I_SENSE
DF_MAX
TG1, 2 t_r
TG1, 2 t_f
BG1, 2 t_r
BG1, 2 t_f
TG/BG t_1D
Transconductance Amplifier g_m
Transconductance Amplifier Gain
Input DC Supply Current
Normal Mode
Shutdown
Soft-Start Charge Current
RUN/SS Pin ON Threshold
RUN/SS Pin Latchoff Arming
RUN/SS Discharge Current
Shutdown Latch Disable Current
Total Sense Pins Source Current
Maximum Duty Factor
Top Gate Transition Time:
Rise Time
Fall Time
Bottom Gate Transition Time:
Rise Time
Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
I_TH = 1.2V, Sink/Source 5µA (Note 4)
I_TH = 1.2V, (g_m • Z_L; No Ext Load) (Note 4)
(Note 5)
V_RUN/SS = 0V
V_RUN/SS = 1.9V
V_RUN/SS Rising
V_RUN/SS Rising from 3V
Soft Short Condition V_EAIN = 0.5V, V_RUN/SS = 4.5V
V_EAIN = 0.5V
Each Channel: V_SENSE1–_{, 2} – = V_SENSE1+_{, 2}+ = 0V
In Dropout
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
(Note 6)
C_LOAD = 3300pF
C_LOAD = 3300pF
C_LOAD = 3300pF Each Driver (Note 6)
3
1.5
1.2
20
– 0.5 –1.2
1.0
1.5
4.1
0.5
2
1.6
– 85 – 60
98
99.5
30
40
30
20
90
mmho
V/mV
mA
40
µA
µA
1.9
V
4.5
V
4
µA
5
µA
µA
%
90
ns
90
ns
90
ns
90
ns
ns
BG/TG t_2D Bottom Gate Off to Top Gate On Delay C_LOAD = 3300pF Each Driver (Note 6)
Top Switch-On Delay Time
90
ns
t_ON(MIN)
Minimum On-Time
Internal V_CC Regulator
V_INTVCC
Internal V_CC Voltage
V_LDO INT INTV_CC Load Regulation
V_LDO EXT EXTV_CC Voltage Drop
V_EXTVCC
EXTV_CC Switchover Voltage
V_LDOHYS EXTV_CC Switchover Hysteresis
VID Parameters
Tested with a Square Wave (Note 7)
6V < V_IN < 30V, V_EXTVCC = 4V
I_CC = 0 to 20mA, V_EXTVCC = 4V
I_CC = 20mA, V_EXTVCC = 5V
I_CC = 20mA, EXTV_CC Ramping Positive
I_CC = 20mA, EXTV_CC Ramping Negative
180
ns
4.8
5.0
5.2
V
0.2
1.0
%
80
160
mV
● 4.5
4.7
V
0.2
V
V_BIAS
R_ATTEN
Operating Supply Voltage Range
Resistance Between ATTENIN
and ATTENOUT Pins
2.7
5.5
V
5
kΩ
ATTEN_ERR
R_PULLUP
VID_THLOW
VID_THHIGH
VID_LEAK
V_{NO_CPU}
Resistive Divider Error
VID0 to VID4 Pull-Up Resistance
VID0 to VID4 Logic Threshold Low
VID0 to VID4 Logic Threshold High
VID0 to VID4 Leakage
NO_CPU Maximum Output Voltage
(Note 8)
V_BIAS < VID0–VID4 < 7V
I_{NO_CPU} = 2mA
● – 0.35
0.25
%
40
kΩ
0.4
V
1.6
V
±1
µA
0.4
V
3819f
3