TSM1052 STMicroelectronics, TSM1052 Datasheet - Page 9

• Manufacturer Part Number: TSM1052
• Description: IC CONTROLLER CC/CV SMPS SOT23-6
• Manufacturer: STMicroelectronics

Specifications of TSM1052

• Function: Charge Management
• Battery Type: All Battery Types
• Voltage - Supply: 1.7 V ~ 18 V
• Operating Temperature: -10°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Number Of Pwm Outputs: 1
• On/off Pin: No
• Adjustable Output: Yes
• Operating Supply Voltage (max): 18V
• Output Current: 100mA
• Output Voltage: -0.3 to 18V
• Synchronous Pin: No
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Pin Count: 6
• Package Type: SOT-23
• Number Of Outputs: Single Output
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 10 C
• Mounting Style: SMD/SMT
• For Use With: 497-8408 - BOARD EVAL LD6562AD/TSM1052497-6242 - BOARD EVAL FOR TSM1052
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6034-2

TSM1052
4.2.2
Note:
Current control
The current loop is controlled via the second trans-conductance operational amplifier, the
sense resistor Rsense, and the optocoupler. The control equation verifies:
Equation 2
where I
control loop.
As an example, with I
The Rsense resistor should be chosen taking into account the maximum dissipation (P
through it during full load operation.
Equation 3
As an example, with I
Therefore, for most adapter and battery charger applications, a quarter-watt, or half-watt
resistor is sufficient. V
voltage reference. Its middle point is tied to the positive input of the current control
operational amplifier, and its foot is to be connected to lower potential point of the sense
resistor as shown in
to provide the best possible accuracy. The current sinking outputs of the two
transconductance operational amplifiers are common (to the output of the IC). This makes
an ORing function which ensures either the voltage control or the current control, driving the
optocoupler's photodiode to transmit the feedback to the primary side.
The relation between the controlled current and the controlled output voltage can be
described with a square characteristic as shown in the following V/I output-power diagram.
(with the power supply of the device indipendent of the output voltage)
lim
is the desired limited current, and V
Figure 15 on page 8.
lim
lim
SENSE
= 1 A, V
= 1 A, and V
a)
b)
threshold is made internally by a voltage divider tied to the V
SENSE
R
R
sense
P
sense
sense
lim
= 200 mV, then R
=
The resistors of this voltage divider are matched
= 200 mV, P
⋅
=
I
V
lim
V
sense
SENSE
sense
I
=
lim
V
⋅
sense
I
lim
is the threshold voltage for the current
lim
SENSE
= 200 mW.
= 200 mΩ.
Application information
lim
9/15
ref
)