LTC3350_15 Datasheet, PDF (7/46 Pages) Linear Technology – High Current Supercapacitor Backup Controller and System Monitor

LTC3350
Electrical Characteristics The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T_A = 25°C (Note 2). V_IN = V_OUT = 12V, V_DRVCC = V_INTVCC unless otherwise
noted.
SYMBOL
t_SU,STO
t_HD,DATO
t_HD,DATI
t_SU,DAT
t_SP
V_SMBALERT
I_SMBALERT
PARAMETER
Stop Condition Set-Up Time
Output Data Hold Time
Input Data Hold Time
Data Set-Up Time
Input Spike Suppression Pulse Width
SMBALERT Output Low Voltage
SMBALERT High-Z Leakage Current
CONDITIONS
I_SINK = 1mA
V_SMBALERT = 5V
MIN TYP MAX
0.6
0
900
0
100
50
200
l
1
UNITS
µs
ns
ns
ns
ns
mV
μA
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 LTC3350 is tested under pulsed load conditions such that
T_J ≈ T_A. The LTC3350E is guaranteed to meet specifications from
0°C to 125°C junction temperature. Specifications over the –40°C to
125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3350I is guaranteed 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. 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 = 34°C/W for the UHF package.
Note 3: The LTC3350 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125˚C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See the Applications Information
section.
Note 5: Measurement error is the magnitude of the difference between the
actual measured value and the ideal value. V_SNSI is the voltage between
VOUTSP and VOUTSN, representing input current. V_SNSC is the voltage
between ICAP and VCAP, representing charge current. Error for V_SNSI and
V_SNSC is expressed in μV, a conversion to an equivalent current may be
made by dividing by the sense resistors, R_SNSI and R_SNSC, respectively.
Typical Performance Characteristics
T_A = 25°C, Application Circuit 4 unless otherwise noted.
Supercapacitor Backup Operation
V_OUT
2V/DIV
V_CAP
2V/DIV
V_IN
2V/DIV
0V
P_BACKUP = 25W
400ms/DIV
BACK PAGE APPLICATION CIRCUIT
3350 G01
HV Electrolytic Backup Operation
P_BACKUP = 25W
V_CAP
5V/DIV
V_OUT
5V/DIV
V_IN
5V/DIV
0V
20ms/DIV
APPLICATION CIRCUIT 6
3350 G02
For more information www.linear.com/LTC3350
Shunt Operation Using V_CAP2
5
V_SHUNT = 2.7V
4
3
I_CHARGE
2
1
I_CAP2
0
–1
2.64 2.65 2.66 2.67 2.68 2.69 2.70 2.71
V_CAP2 (V)
3350 G03
3350fb
7