THV3058 Datasheet, PDF (12/21 Pages) THine Electronics, Inc. – 3CH (Buck/Boost) 2CH CP 1CH HVLDO Controller

THV3058_Rev.1.00_E
● DC/DC Converter CH-1, CH-2, CH-3
CH-1, CH-2 and CH-3 are PWM controllers. CH-1 is for Boost, CH2 is synchronous rectifier Buck and CH-3 is fixed
3.3V for Buck. Implementing over current protection circuit. The maximum duty cycle of CH-1 is internally limited to
86%, CH-2, CH-3 to 84%.
● Charge Pump Circuit VGH, VGL
VGH is positive charge pump circuit, and VGL is negative one. These also operate in PFM mode. The pulse duty of VGH
is fixed 50%, VGL is fixed 18%.
● High Voltage LDO
Figure 3 shows the circuit of High Voltage LDO. Connect to an external output capacitor (Typ:2.2μF). High voltage
LDO has built-in auto-recovery current limit function. The threshold current is 250mA. The output voltage is given by
the following formula.
Vhldo = VREF × _⎝⎛1 + ^RR----¹²-_⎠⎞ = 1.2 × _⎝⎛1 + ^RR----¹²-_⎠⎞
VREF
-
+
V_ VGH
cur_ limit
Vhldo
OUT_ HLDO
R1 _2.2uF
INV_ HLDO
R2
Figure 3. High Voltage LDO Circuit
● VGH_OK
VGH_OK pin is open drain output of NMOS pull-down transistor. When the power supply is turned On, VGH_OK pin is
Gnd level. When the voltage on VGH reaches 85% of normal output voltage, NMOS transistor is turned Off.
Copyright©2010 THine Electronics, Inc.
12/21
THine Electronics, Inc.