TOKO TK11821MTL, TK11821MMG, TK11821MBX Datasheet
TK11821
B
D
G
S
DC-DC CONVERTER
FEATURES
■ Very Low Noise
■ Very Small Size
■ Few External Components
■ Wide Supply Voltage Range (0.9 to 10 V)
■ Sinewave Oscillator
■ Selectable Output Voltages
DESCRIPTION
The TK11821 is a low power, low input voltage DC-DC
converter. The device has been optimized for variable
capacitance diode and PIN photodiode bias applications. It
generates 10 Vdc and 24 Vdc output voltages from an input
voltage as low as 0.9 V.
Since the built-in high frequency oscillator generates
sinewaves, the TK11821 produces very low RF interference noise. The internal oscillator is capable of operation
at frequencies as high as 6-8 MHz, therefore, interference
filtering is simple and effective. This unique feature makes
the TK11821 ideally suitable for RF and fiber optic receiver
applications.
APPLICATIONS
■ Variable Capacitance and PIN Photodiode Bias
■ Portable Instrumentation
■ Radio Control Systems
■ Mobile Radios
■ Cellular Telephones
■ Cordless Telephones
■ Fiberoptic Receivers
■ Local Area Network (LAN) Receivers
■ Battery Operated Equipment
TK11821M
1
OSC
2
YPASS
V
V
D
3
4
O
821
A21
8
V
FB
7
GN
V
6
IN
T1
5
The device is capable of operation in the 0.9 to 10 V power
supply voltage range.
The output voltage is 24 V when T1 is not connected. When
T1 is connected to VO, the output voltage is set to 10 V.
The TK11821 is available in an 8-pin plastic surface mount
(MFP-8) package. External inductive components are also
available.
ORDERING INFORMATION
V
6
IN
BLOCK DIAGRAM
V
FB
5
Feedback
Control
OSC
V
D
1
2
V
4
O
TK11821M
Tape/Reel Code
5
ND
7
V REF
TAPE/REEL CODE
BX: Bulk/Bag
TL: Tape Left
MG: Magazine
January, 1996 TOKO, Inc.
1-30-96
T1
3
BYPAS
Page 1
TK11821
ABSOLUTE MAXIMUM RATINGS
Input Voltage............................................................ 10 V
Output Voltage ......................................................... 26 V
Output Current ..................................................... 0.5 mA
Operating Voltage Range............................... 0.9 to 10 V
Power Dissipation (Note 1) ................................ 350 mW
ELECTRICAL CHARACTERISTICS
Test conditions: VIN = 0.9 V → 2.0 V
Operating Conditions: V
SYMBOL PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
I
V
CC
O
Input Current
Output Voltage
= 1.1 V, TA = 25 °C unless otherwise specified.
IN
IO = 0 , VO = 10 V 3.5 7.0 mA
IO = 50 µA, VO = 10 V 5.5 9.0 mA
IO = 0 µA, 1.6 V ≤ VIN ≤ 2.0 V 22.5 24.0 25.5 V
VO - T1 shorted, IO = 50 µA 9.6 10.0 10.4 V
Junction Temperature .......................................... 150 °C
Storage Temperature Range ...................-55 to +150 °C
Operating Temperature Range .................-20 to +70 °C
Lead Soldering Temp. (10 sec.)........................... 260 °C
I
O
Output Current VO - T1 shorted 90 100 µA
Load Reg Load Regulation Note 2 0.1 0.35 %
∆VO/T
V
OSC-S
f
OSC
A
Output Voltage
Temperature Dependency
Oscillation Starting Voltage IO = 0 µA 0.75 V
Oscillation Frequency IO = 0 µA, Note 2 4.0 MHz
VO = 24 V, IO = 50 µA +2.3 mV/°C
VO = 10 V, IO = 50 µA -1.5 mV/°C
ELECTRICAL CHARACTERISTICS
Test conditions: VIN = 1.8 V → 10.0 V
Operating Conditions: V
SYMBOL PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
I
V
I
CC
O
O
Input Current
Output Voltage
Output Current VO - T1 shorted 90 100 µA
Load Reg Load Regulation Note 2 0.1 0.35 %
∆VO/T
A
Output Voltage
Temperature Dependency
= 3.0 V, TA = 25 °C unless otherwise specified.
IN
IO = 0 , VO = 10 V 3.5 7.0 mA
IO = 50 µA, VO = 10 V 5.5 9.0 mA
IO = 0 µA, 1.6 V ≤ VIN ≤ 2.0 V 22.5 24.0 25.5 V
VO - T1 shorted, IO = 50 µA 9.6 10.0 10.4 V
VO = 24 V, IO = 50 µA +2.3 mV/°C
VO = 10 V, IO = 50 µA -1.5 mV/°C
V
OSC-S
f
OSC
Note 1: Power dissipation must be derated at the rate of 3 mW/°C for operation at TA = 25 °C and above.
Note 2: Use the same value for L that was used in the measurement circuit.
Note 3: Output Voltage Variation = (∆V
Note 4: The circuit constants will be changed by the input voltage at the 0.9 V to 2.0 V range and 1.8 V to 10 V range.
Page 2
Oscillation Starting Voltage IO = 0 µA 1.5 V
Oscillation Frequency IO = 0 µA, Note 2 3.5 MHz
O1/VO1
) X 100 (%), ∆V
= VO1 (no load) - V
O1
1-30-96
O1 (IO
= 50 µA).
January, 1996 TOKO, Inc.
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