The JTMA7088, two-phase PWM control IC, provides a precision(2)

　　七,功能概述
Layout Consideration

In any high switching frequency converter, a correct lay-out is important to ensure proper operation of the
regulator. With power devices switching at higher frequency, the resulting current transient will cause volt-
age spike across the interconnecting impedance and parasitic circuit elements. As an example, consider the
turn-off transition of the PWM MOSFET. Before turn-off condition, the MOSFET is carrying the full load current.
During turn-off, current stops flowing in the MOSFET and is freewheeling by the lower MOSFET and parasitic diode.
Any parasitic inductance of the circuit generates a large voltage spike during the switching interval. In general,
using short and wide printed circuit traces should mini-mize interconnecting impedances and the magnitude of
voltage spike. And signal and power grounds are to be kept separating and finally combined to use the ground
plane construction or single point grounding. The best tie-point between the signal ground and the power ground
is at the negative side of the output capacitor on each channel, where there is less noise. Noisy traces beneath
the IC are not recommended. Below is a checklist for your layout:

Layout Consideration
- Keep the switching nodes (UGATE, LGATE, BOOT, and PHASE) away from sensitive small signal nodes(VFB,
VTTREF, and CS) since these nodes are fast moving signals. Therefore, keep traces to these nodes as short
as possible and there should be no other weak signal traces in parallel with theses traces on any layer.
- The signals going through theses traces have both high dv/dt and high di/dt, with high peak charging and dis-
charging current. The traces from the gate drivers to the MOSFETs (UGATE and LGATE) should be short and wide.
- Place the source of the high-side MOSFET and the drain of the low-side MOSFET as close as possible. Minimiz-
ing the impedance with wide layout plane between the two pads reduces the voltage bounce of the node.

- Decoupling capacitor, the resistor dividers, boot capacitors, and current limit stetting resistor should be

close their pins. (For example, place the decoupling ce-ramic capacitor near the drain of the high-side MOSFET
as close as possible. The bulk capacitors are also placed near the drain).
- The input capacitor should be near the drain of the up-per MOSFET; the high quality ceramic decoupling capaci-
tor can be put close to the VCC and GND pins; the VTTREF decoupling capacitor should be close to the VTTREF pin
and GND; the VDDQ and VTT output capacitors should be located right across their output pin as close as pos-
sible to the part to minimize parasitic. The input capacitor GND should be close to the output capacitor GND and
the lower MOSFET GND.
- The drain of the MOSFETs (VIN and PHASE nodes) should be a large plane for heat sinking. And PHASE pin
traces are also the return path for UGATE. Connect this pin to the converter’s upper MOSFET source.
- The JTMT8868 used ripple mode control. Build the re- sistor divider close to the VFB pin so that the high imped-
ance trace is shorter. And the VFB pin traces can’t be closed to the switching signal traces (UGATE, LGATE,
BOOT, and PHASE).
- The PGND trace should be a separate trace, and inde-pendently go to the source of the low-side MOSFETs for
current limit accuracy.
八,相关产品

Part_No	Package & Pins	Topology	Architecture	Phase	No. of PWM Outputs	Output Current (max)(A)	Input Voltage (V)		Reference Voltage(V)	Bias Voltage (typ) (V)	Quiescent Current (typ)(uA)
Part_No	Package & Pins	Topology	Architecture	Phase	No. of PWM Outputs	Output Current (max)(A)	min	max	Reference Voltage(V)	Bias Voltage (typ) (V)	Quiescent Current (typ)(uA)
JTMA7068	SOP-14	Buck	VM	1	1	30	2.9	13.2	0.9	12	8000
	QSOP-16
	QFN4x4-16
JTMA7065	SOP-8	Buck	VM	1	1	20	2.9	13.2	0.8	12	5000
JTMA7065C	SOP-8	Buck	VM	1	1	20	2.9	13.2	0.8	12	5000
JTMA7098	QFN4x4-24	Multiphase	VM	2	1	60	3.1	13.2	0.6	12	5000
JTMA7120	SOP-8	Buck	VM	1	1	20	2.2	13.2	0.8	5月12日	2100
JTMA7120A	SOP-8	Buck	VM	1	1	20	2.2	13.2	0.8	5月12日	2100
JTMA7037/A/B	SOP-8	Buck	VM	1	1	5	5	13.2	1.25 / 0.8	5月12日	3000
JTMA7037/A/B	TSSOP-8	Buck	VM	1	1	5	5	13.2	1.25 / 0.8	5月12日	3000
JTMA7057	SOP-8	Buck	VM	1	1	10	3.3	5.5	0.8	5	2100
JTMA7062B	SOP-14	Buck	VM	1	1	10	5	13.2	0.8	12	2000
JTMA7066	TSSOP-24	Buck	VM	1	2	20	5	13.2	0.6	5月12日	4000
JTMA7066	QFN5x5-32	Buck	VM	1	2	20	5	13.2	0.6	5月12日	4000
JTMA7067N	SOP-14	Buck	VM	1	1	30	2.9	13.2	0.9	12	4000
	QSOP-16
	QFN-16
JTMA7073	SOP-14	Buck	VM	1	1	30	2.2	13.2	0.6	12	5000
JTMA7073A	SOP-14	Buck	VM	1	1	30	2.2	13.2	0.6	12	5000
JTMA7074	SOP-14	Buck	VM	1	1	25	2.2	13.2	0.8	12	5000
JTMA7095/A	LQFP7x7-48	Buck	VM	1	6	0.015	1.4	6.5	-	5	1800
	TQFN7x7-48	Boost
		Flyback
JTMA7116	TSSOP-24P	Buck	VM	1	2	20	2.97	5.5	0.8	5月12日	5000
JTMA7063	SOP-14	Buck	VM	1	1	10	5	13.2	0.8	12	3000
JTMA7064	SOP-8-P	Buck	VM	1	1	30	2.9	13.2	1.2	12	3000
JTMA7064	DIP-8	Buck	VM	1	1	30	2.9	13.2	1.2	12	3000
JTMA7108	SSOP-28	Buck	VM	1	2	20	5	24	0.9	5	1200
JTMA7108	QFN4x4-24	Buck	VM	1	2	20	5	24	0.9	5	1200
JTMA7158	SOP-20	Buck	VM	1	2	20	2.2	13.2	0.6	5月12日	4000
JTMA7181	SOP-8		VM	1	2	-	-	-	-	5月12日	550
JTMA7181	DFN3x3-10		VM	1	2	-	-	-	-	5月12日	550
JTMA38HC/42/3/4/5A	DIP-8	Buck	VM	1	1	1	1.2	9	24	5	9 ~ 24
	SOP-8	Boost
		Flyback
		Forward
JTMA7138	SSOP-16	Buck	VM	1	1	25	3	25	0.6	5	1700
	QFN4x4-16
	TQFN3x3-16
JTMA7199	TDFN3x3-10	Buck	COT	1	1	25	3	25	0.5	5	350
JTMA8700	QFN4x4-24	Buck	CM	2	1	40	4.5	13.2	0.6	5月12日	4000
JTMA8720B	SOP8-P	Buck	VM	1	1	20	3	13.2	0.8	5月12日	2500
JTMA8720B	TDFN3x3-10	Buck	VM	1	1	20	3	13.2	0.8	5月12日	2500
JTMA8722A/B/C/D	SOP8-P	Buck	VM	1	1	25	3	13.2	0.6 /0.8	5月12日	1200
JTMA8723	TDFN3x3-10	Buck	VM	1	1	25	4	13.2	0.8	5月12日	2000
JTMA8724	TDFN3x3-10	Buck	COT	1	1	25	4.5	25	0.6	5月12日	80
JTMA8725/A	SOP-8P	Buck	VM	1	1	25	4.5	13.2	0.8	5月12日	16000
JTMA8726	TQFN3x3-10	Buck	VM	1	1	25	4.5	13.2	0.6	5月12日	2500
JTMA8727/L	TDFN3x3-10	Buck	COT	1	1	30	3	25	0.8	5月12日	2000
JTMA8728	TQFN3x3-16	Buck	COT	1	1	30	1.8	28	0.6	5	600
JTMA8732	QFN4x4-24	Buck	VM	2	1	50	4.5	13.2	0.6	5月12日	5000
JTMA8811	TQFN4x4-24	Buck	COT	1	2	15	6	25	2	N	550
JTMA8812	TQFN4x4-24	Buck	COT	1	2	15	6	25	2	N	550
JTMA8813/A	TQFN4x4-24	Buck	COT	1	2	20	3	28	0.75	5	800
JTMA8813/A	TQFN3x3-20	Buck	COT	1	2	20	3	28	0.75	5	800
JTMA8814	TQFN3x3-16	Buck	COT	1	1	20	1.8	28	0.75	5	400
JTMA8815	QFN3.5x3.5-14	Buck	COT	1	1	20	1.8	28	0.75	5	400
JTMA8815	TQFN3x3-16	Buck	COT	1	1	20	1.8	28	0.75	5	400
JTMA8816	TQFN3x3-16	Buck	COT	1	2	20	1.8	28	0.75	5	400
JTMA8819	QFN3x3-20	Buck	COT	1	2	20	3	28	1.8 /1.5 /0.5	5	740
JTMA8819	TQFN3x3-16	Buck	COT	1	2	20	3	28	1.8 /1.5 /0.5	5	740
JTMA8820	TQFN4x4-24	Buck	CM	1	2	15	5	28	0.5	N	3000
JTMA8820	QFN3x3-20	Buck	CM	1	2	15	5	28	0.5	N	3000
JTMA8821	TDFN3x3-10	Buck	COT	1	1	20	1.8	28	0.5	5	250
JTMA8822/C	TQFN3x3-20	Buck	COT	1	2	15	6	25	2	N	550
JTMA8823A/B	TQFN3x3-20	Buck	COT	1	2	15	5.5	25	0.6	N	50
JTMA8868	TQFN3x3-20	Buck	COT	1	2	20	3	28	0.75	5	180
JTMA7088	QFN4x4-24	Multiphase	VM	2	1	60	3.1	13.2	0.85	12	5000
JTMA7165A/B/C	SOP-8P	Buck	VM	1	1	20	2.9	13.2	0.8	12	16000
JTMA7159A	SOP-20	Buck	VM	2	2	30	10	13.2	1	12	5000
JTMA8828	TDFN3x3-10	Buck	COT	1	1	25	1.8	28	0.7	5	250
JTMA8728	TQFN 3x3 16	Buck	COT	1	1	30	1.8	28	0.6	5	600