TSM105CD ,CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER FOR BATTERY CHARGERS AND ADAPTORSELECTRICAL CHARACTERISTICSTamb = 25°C and Vcc = +5V (unless otherwise specified) S ..
TSM106ID ,Dual Operational Amplifier and Voltage ReferenceElectrical characteristics for operator 2 (independant op-amp): VCC+ = +5V, VCC = Ground, Vo = 1.4V ..
TSM106IDT ,Dual Operational Amplifier and Voltage ReferenceElectrical characteristics for operator 2 (independant op-amp): VCC+ = +5V, VCC = Ground, Vo = 1.4V ..
TSM107IDT ,Triple Operational Amplifier and Voltage Reference-+-+-+TSM107Triple Operational Amplifier and Voltage ReferenceOperational Amplifier:■ Medium bandwi ..
TSM108ID ,AUTOMOTIVE SWITCH MODE VOLTAGE & CURRENT CONTROLLERapplications. Part Number Temperature RangeDTSM108 can easily be configured for very wideTSM108I -4 ..
TSM108IDT ,AUTOMOTIVE SWITCH MODE VOLTAGE & CURRENT CONTROLLERTSM108AUTOMOTIVE SWITCH MODEVOLTAGE AND CURRENT CONTROLLER■ CURRENT MEASUREMENT ON OUTPUT APPLICATI ..
UC2827DW-1G4 ,Buck Current/Voltage Fed Push-Pull PWM Controllers 24-SOIC -40 to 85ELECTRICAL CHARACTERISTICSUnless otherwise spsecified, V = 15 V, V = 14.3 V, C = 340 pF, R = 10 kΩ, ..
UC2827DW-2 ,1FEATURESDESCRIPTION• Ideal for Multiple Output and/or HighThe UC3827 family of controller devices p ..
UC2827DW-2 ,1ELECTRICAL CHARACTERISTICSUnless otherwise spsecified, V = 15 V, V = 14.3 V, C = 340 pF, R = 10 kΩ, ..
UC2827DW-2 ,1features of the UC3827 include bidirectional synchronization capability, user programmableoverlap t ..
UC2827DWTR-1 ,1FEATURESDESCRIPTION• Ideal for Multiple Output and/or HighThe UC3827 family of controller devices p ..
UC2827N-2 ,1features of the UC3827 include bidirectional synchronization capability, user programmableoverlap t ..
TSM105CD
CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROLLER FOR BATTERY CHARGERS AND ADAPTORS
CONSTANT VOLTAGE AND CONSTANT CURRENT CONTROL�
LOW VOLTAGE OPERATION PRECISION INTERNAL VOLTAGE REFER-
ENCE LOW EXTERNAL COMPONENT COUNT CURRENT SINK OUTPUT STAGE�
EASY COMPENSATION LOW AC MAINS VOLTAGE REJECTION
DESCRIPTIONTSM105 is a highly integrated solution for SMPS
applications requiring CV (constant voltage) and
CC (constant current) mode.
TSM105 integrates one voltage reference, two
operational amplifiers (with ORed outputs - com-
mon collectors), and a current sensing circuit.
The voltage reference combined with one opera-
tional amplifier makes it an ideal voltage control-
ler, and the other low voltage reference combined
with the other operational amplifier makes it an
ideal current limiter for output low side current
sensing.
The current threshold is fixed, and precise.
The only external components are:
* a resistor bridge to be connected on the output of
the power supply (adapter, battery charger) to set
the voltage regulation by dividing the desired out-
put voltage to match the internal voltage reference
value.
* a sense resistor whose value and allowable dis-
sipation power need to be chosen according to the
internal voltage threshold.
* optional compensation components (R and C).
TSM105, housed in one of the smallest package
available, is ideal for space shrinked applications
such as adapters and battery chargers.
APPLICATIONS ADAPTERS BATTERY CHARGERS
ORDER CODE
L = Tiny Package (SOT23-5) - only available in Tape & Reel (LT)
D = Small Outline Package (SO) - also available in Tape & Reel (DT)
PIN CONNECTIONS (top view)
TSM105CONSTANT VOLTAGE AND CONSTANT CURRENT
CONTROLLER FOR BATTERY CHARGERS AND ADAPTORS
TSM105
PIN DESCRIPTION
SOT23-5 Pinout
SO8 Pinout
ABSOLUTE MAXIMUM RATINGS
TSM105OPERATING CONDITIONS
ELECTRICAL CHARACTERISTICSTamb = 25°C and Vcc = +5V (unless otherwise specified)
If the voltage on VCTRL (the negative input of the amplifier) is higher than the positive amplifier input (Vref=1.210V), and it is increased
by 1mV, the sinking current at the output OUT will be increased by 3.5mA. The internal Voltage Reference is set at 1.210V (bandgap reference). The voltage control loop precision takes into account the cumulative
effects of the internal voltage reference deviation as well as the input offset voltage of the trans-conductance operational amplifier. The
internal Voltage Reference is fixed by bandgap, and trimmed to 0.5% accuracy at room temperaure. When the positive input at ICTRL is lower than -200mV, and the voltage is decreased by 1mV, the sinking current at the output OUT will
be increased by 7mA. The internal current sense threshold is set to -200mV. The current control loop precision takes into account the cumulative effects of the
internal voltage reference deviation as well as the input offset voltage of the trans-conductance operational amplifier.
TSM105 In the above application schematic, the TSM105 is used on the secondary side of a flyback adapter (or
battery charger) to provide an accurate control of voltage and current. The above feedback loop is made
with an optocoupler.
Figure 1 : Internal Schematic
Figure 2 : Typical Adapter or Battery Charger Application Using TSM105
1. Voltage and Current Control
1.1. Voltage ControlThe voltage loop is controlled via a first transcon-
ductance operational amplifier, the resistor bridge
R1, R2, and the optocoupler which is directly con-
nected to the output.
The relation between the values of R1 and R2
should be chosen as writen in Equation 1.
R1 = R2 x Vref / (Vout - Vref) Eq1
where Vout is the desired output voltage.
To avoid the discharge of the load, the resistor
bridge R1, R2 should be highly resistive. For this
type of application, a total value of 100KΩ (or
more) would be appropriate for the resistors R1
and R2.
As an example, with R2 = 100KΩ, Vout = 4.10V,
Vref = 1.210V, then R1 = 41.9KΩ.
Note that if the low drop diode should be inserted
between the load and the voltage regulation resis-
tor bridge to avoid current flowing from the load
through the resistor bridge, this drop should be
taken into account in the above calculations by re-
placing Vout by (Vout + Vdrop).
1.2. Current ControlThe current loop is controlled via the second
trans-conductance operational amplifier, the
sense resistor Rsense, and the optocoupler.
The control equation verifies:
Rsense x Ilim = Vsense eq2
Rsense = Vsense / Ilim eq2’
where Ilim is the desired limited current, and
Vsense is the threshold voltage for the current
control loop.
As an example, with Ilim = 1A, Vsense = -200mV,
then Rsense = 200mΩ.
Note that the Rsense resistor should be chosen
taking into account the maximum dissipation
(Plim) through it during full load operation.
Plim = Vsense x Ilim. eq3
As an example, with Ilim = 1A, and Vsense =
200mV, Plim = 200mW.
Therefore, for most adapter and battery charger
applications, a quarter-watt, or half-watt resistor to
make the current sensing function is sufficient.
Vsense threshold is achieved internally by a re-
sistor bridge tied to the Vref voltage reference. Its
middle point is tied to the positive input of the cur-
rent control operational amplifier, and its foot is to
be connected to lower potential point of the sense
resistor as shown on the following figure. The re-
sistors of this bridge are matched to provide the
best precision possible
The current sinking outputs of the two trans-con-
nuctance operational amplifiers are common (to
the output of the IC). This makes an ORing func-
tion which ensures that whenever the current or
the voltage reaches too high values, the optocou-
pler is activated.
The relation between the controlled current and
the controlled output voltage can be described
with a square characteristic as shown in the fol-
lowing V/I output-power graph.
Figure 3 : Output voltage versus output current
2. CompensationThe voltage-control trans-conductance operation-
al amplifier can be fully compensated. Both its out-
put and the negative input are directly accessible
for external compensation components.
TSM105PRINCIPLE OF OPERATION AND APPLICATION HINTS
TSM105 An example of a suitable compensation network is
shown in Fig.2. It consists of a capacitor
Cvc1=2.2nF and a resistor Rcv1=470KΩ in series,
connected in parallel with another capacitor
Cvc2=22pF.
The current-control trans-conductance operation-
al amplifier has to be compensated in a different
way, since its negative input is connected to
ground. A series connection of a capacitor
Cic1=100nF and a resistor Ric1=22Ω can be put
between OUT and GND to stabilize the global reg-
ulation loop.
3. Start Up and Short Circuit ConditionsUnder start-up or short-circuit conditions the
TSM105 is not provided with a high enough supply
voltage. This is due to the fact that the chip has its
power supply line in common with the power sup-
ply line of the system.
Therefore, the current limitation can only be en-
sured by the primary PWM module, which should
be chosen accordingly.
If the primary current limitation is considered not to
be precise enough for the application, then a suffi-
cient supply for the TSM105 has to be ensured un-
der any condition. It would then be necessary to
add some circuitry to supply the chip with a sepa-
rate power line. This can be achieved in numer-
ous ways, including an additional winding on the
transformer.
The following schematic shows how to realise a
low-cost power supply for the TSM105 (with no
additional windings).
Please pay attention to the fact that in the particu-
lar case presented here, this low-cost power sup-
ply can reach voltages as high as twice the volt-
age of the regulated line. Since the Absolute Max-
imum Rating of the TSM105 supply voltage is 14
V, this low-cost auxiliary power supply can only be
used in applications where the regulated line volt-
age does not exceed 7 V.
Figure 4 :
