TCM828ECT713 Microchip Technology, TCM828ECT713 Datasheet - Page 13

• Manufacturer Part Number: TCM828ECT713
• Description: IC CHARGE PUMP CONV SOT23A-5
• Manufacturer: Microchip Technology
• Type: Switched Capacitor (Charge Pump), Doubler, Invertingr

Specifications of TCM828ECT713

• Package / Case: SOT-23-5, SC-74A, SOT-25
• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: -1.5 ~ -5.5 V, ±3 ~ ±11 V
• Current - Output: 25mA
• Frequency - Switching: 12kHz
• Voltage - Input: 1.5 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Power - Output: 240mW
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Function: Inverting, Step Up
• Output Voltage: - 1.5 V to - 5.5 V, 3 V to 11 V
• Output Current: 25 mA
• Maximum Operating Temperature: 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 158-2031-2; 158-2031-2; TCM828ECT713TR

5.0
5.0.1
The
conversion, but do not provide regulation. The output
voltage will droop in a linear manner with respect to
load current. The value of this equivalent output
resistance is approximately 25Ω nominal at +25°C and
VIN = +5V. VOUT is approximately – 5V at light loads,
and droops according to the equation below:
5.0.2
The overall power efficiency of the charge pump is
affected by four factors:
1.
2.
3.
4.
Most of the conversion losses are due to factors 2, 3
and 4 above. These losses are shown in
EQUATION 5-1:
The 1/(f
output resistance of an ideal switched capacitor circuit
(Figures 5-1 and
© 2010 Microchip Technology Inc.
P
≅
LOSS 2 3 4
I OUT 2
V
V
Losses from power consumed by the internal
oscillator, switch drive, etc. (which vary with
input
frequency).
I
MOSFET switches on-board the charge pump.
Charge pump capacitor losses due to effective
series resistance (ESR).
Losses that occur during charge transfer (from
the commutation capacitor to the output
capacitor) when a voltage difference between
the two capacitors exists.
2
DROOP
OUT
R losses due to the on-resistance of the
TCM828/TCM829
(
OSC
, ,
APPLICATIONS INFORMATION
×
= –(V
OUTPUT VOLTAGE
CONSIDERATIONS
CHARGE PUMP EFFICIENCY
voltage,
)(C1) term in
--------------------------
(
)
= I
f OSC
=
OUT
IN
1
I
OUT
5-2).
)C1
–V
× R
DROOP
2
+
temperature
×
OUT
8R SWITCH
R
Equation 5-1
OUT
devices
)
+
perform
4ESR C1
and
is the effective
Equation
oscillator
+
ESR C2
voltage
5-1.
The losses in the circuit due to factor 4 above are also
shown in
shown in
EQUATION 5-2:
EQUATION 5-3:
FIGURE 5-1:
Model.
FIGURE 5-2:
Resistance.
P
LOSS 4 ( )
V
+
V
R
V
+
EQUIV
RIPPLE
Equation
C1
TCM828/TCM829
Equation
=
–
[
R
(
2V
=
0.5
EQUIV
=
f
OUT
-------------- -
f
) C1
(
×
----------------------------
(
1
f
5-3.
C1
OSC
V
5-2. The output voltage ripple is
) V (
RIPPLE
I
OUT
Ideal Switched Capacitor
Equivalent Output
IN
) C2
(
2
+
]
V
)
C2
C2
×
OUT
+
f
OSC
2 I
(
2 )
OUT
+
DS21488B-page 13
(
0.5
) ESR
(
) C2
R
(
R
L
L
V
) V
(
C2
OUT
V
RIPPLE
OUT
)
2
–