TC115_13 Datasheet, PDF (2/14 Pages) Microchip Technology – PFM/PWM Step-Up DC/DC Converter

TC115
1.0 ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings†
Power Supply Voltage (PS) ...............................................12V
Power Dissipation ......................................................500 mW
LX Sink Current......................................................400 mA pk
SHDN Input Voltage ..........................................................12V
Operating Temperature Range........................-40°C to +85°C
Storage Temperature Range .........................-40°C to +125°C
† Stresses above those listed under "Absolute Maximum
Ratings" may cause permanent damage to the device. These
are stress ratings only and functional operation of the device
at these or any other conditions above those indicated in the
operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability.
PIN FUNCTION TABLE
Symbol
NC
PS
SHDN
LX
GND
Description
Not connected
Power and voltage sense input
Shutdown input
Inductor switch output
Ground terminal
DC CHARACTERISTICS
Electrical Specifications: Unless otherwise noted, V_OUT = 5V, T_A = +25°C. Circuit configuration is illustrated in Figure 5-1.
Parameters
Sym
Min
Typ
Max
Units
Conditions
Operating Supply Voltage
Start-Up Supply Voltage
LX Maximum Sink Current
LX Limit Frequency
LX Limit Voltage
No Load Supply Current
Boost Mode Supply Current
Standby Supply Current
Shutdown Supply Current
Oscillator Frequency
Output Voltage
LX Output ON Resistance
Duty Cycle
(PFM Operating Mode)
V_IN
0.9
—
10.0
V Note 5
V_START
—
—
0.9
V I_OUT = 1 mA
I_LXMAX
—
—
350
mA
f_LIM
—
200
—
kHz V_LX = VLX_LIM
VLX_LIM
0.7
—
1.3
V Note 2
I_DD
—
13
26
µA I_OUT = 0, V_IN = V_OUT x 0.8 (Note 3)
I_CC
—
80
135
µA No external components,
V_IN = (0.95 x V_OUT) applied to PS (or
V_DD) input
I_STBY
—
9
17
µA No external components,
V_IN = (1.1 x V_OUT) applied to PS
(or V_DD) input
I_SD
—
—
0.5
µA SHDN = 0V
f_OSC
85
100
115
kHz Note 2, Note 4
V_OUT V_R x 0.975 V_R V_R x 1.025 V V_IN = 2.2V minimum (Note 1)
Rswon
—
1.4
2.4
 V_LX = 0.4V
PFMDUTY
10
17
25
% No external components
Maximum Duty Cycle
MAX-
80
87
92
% Note 4
DUTY
Soft Start Time
Efficiency
t_SS
4
10
20
msec
h
—
85
—
%
SHDN Input Logic High
V_IH
0.75
—
—
V
SHDN Input Logic Low
V_IL
—
—
0.20
V
Note 1:
2:
V_R is the nominal factory-programmed output voltage setting.
VLX_LIM is the voltage on the LX pin (with internal switch ON) that will cause the oscillator to run at twice nominal
frequency in to limit the switch current through the internal N-channel switching transistor.
3: Measured with D₁ = MA735 (reverse current < 1 µA at a reverse voltage of 10V).
4: With TC115 operating in PWM mode.
5: See Section 4.4, “Behavior When V_IN is Greater Than the Factory-Programmed V_OUT Setting”.
DS21361D-page 2
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